5 Ninja Methods I Used to Find Competitors' Customers

Finding your competitors’ customers shouldn’t be hard. No spy movie-esque rooftop break-ins, red security lasers, or CEO computer hacking.

And you won’t need to, because I’ve found 5 easy ways (free and paid) to help you find your competitors’ customers quickly and most importantly, legally.

I challenged myself to find Intercom’s customers using all these methods, and these are my results. 

I’ll go through how to do each method, the data’s legalities, and the pros and cons, so you can choose which is the best. I may be biased, but I’d recommend Sapiengraph as the easiest one ;)

1. Look for customer testimonials on websites (Free but menial and time-consuming)

2. Search for competitors’ customers using web-scraping tools
   a. Search on Built With (Free to search. From $295 per month for a full list) 
   b. Search on NerdyData (Only one download for free account, unlimited download for $200 per month)*

3. Look for customer reviews on review websites
   a. Check on Featured Customers (Free but no customer’s contact details)
   b. Check on G2 (Free but no customer’s contact details)

4. Search for competitors’ customers on Twitter/X (Free but menial and time-consuming)

5. Search using Sapiengraph’s Customers Prospector (Free to search, 30 credits per unlocked results, $49 per month to buy credits)*

1. Look for customer testimonials on websites

This is a classic one. The easiest way to find your competitors’ customers is to check their websites.

This method works best if your competitors take their website presence seriously or are established businesses.

Why this method can help find competitors’ customers

Companies have to provide social proof that their services are well-loved. They usually have testimonials and case studies you can look for. Plus, many websites also display their customers’ full names, titles, and company names.

How I performed this method to find customers

Usually, you can find testimonials on the main page. Some companies put them top of the page, some put them near the bottom. 

This is an example from Intercom’s landing page.

For case studies, they are most likely found in their blog, like this one from Proxycurl’s interview with CoffeeSpace.

After you do this, you can send them invitations on LinkedIn to connect or send them a message. Even better, you can compile them all in Google Sheets and use a data enrichment tool (like Sapiengraph’s) to find their emails.

Pros of using testimonials

Easy and straightforward. You know for sure that these are your competitors’ customers.

Cons of using testimonials

• If they’re giving interviews and testimonials, they're most likely on good terms with your competitor. It would be hard to steal them for yourself.
• You have to manually search for their contact information on LinkedIn or other sources

2. Search for competitors’ customers using web-scraping tools

You’ll get the most out of this method if your competitor is a SaaS company that requires code to be added to the customer’s website to work.

Usually, SaaS companies will insert a small piece of code directly onto their customer’s webpage for the software to work. This also means when you inspect the code (right-click + inspect), it can be seen by the public.

Why this method can help find competitors' customers

So, I used BuiltWith and NerdyData for this method. Both tools will crawl through millions of websites and check their source code to determine the different software these websites are using.

How I use BuiltWith to find competitors’ customers  

BuiltWith is a tool that helps you identify the different types of software a website is using. It finds this information by crawling 600 million websites worldwide.

With a quick search on BuiltWith, you can easily find out which websites are currently using your competitor’s product. Let’s say Intercom is your competitor.

First, search Intercom and click on the Live Websites option.

Then, you’ll land on a page that lists all of the websites currently using Intercom. Basically, Intercom’s current customers.

For each row, there’s a drop-down button to the right, where you can find details like their address, phone number, employees' LinkedIn profiles, social media links, and most importantly, the company’s email addresses.

Do note that this gives you the company’s general email address, and not their employees. If you want a better shot at getting a reply, you will most likely need to find employee data too. You can do so with data enrichment tools as well 😄

You can also download the full list by clicking on the big red Download Lead List button at the top right of the screen. When you’ve clicked that, a report will appear on your dashboard.

Custom Export lets you customize for the information you need. Click Generate Export to get a partial exported list.

Up to this point, everything has been free. But if you want the full customer list, you'll need to upgrade to at least the Basic plan which is $295 per month.

Pros of using BuiltWith

Fresh and legal data.

I talked to BuiltWith co-founder, Gary Brewer. 

He said their data is “super fresh.”

Basically, one month and a half.

For me, that’s decent. I would be happy with that. Since that’s the "worst case", the data could be updated even sooner than that.

They take into account data collection legality too.

Brewer also said, “There's no Personally Identifiable Information (PII) for Europe or California, and you can turn off ALL PII.” PII is any info linked to a person that can reveal their identity such as a Social Security number, full name, email, or phone number.

BuiltWith lets you select your compliance. 

Other benefits include:

• Great if your competitor embeds their code on their customers’ websites.
• Immediately get contact information

Cons of using BuiltWith

• If your competitor is not a business that embeds their code on their customers’ websites, it’s very unlikely you’ll find their customers. When they don’t embed, it means they handle interactions and data through other methods that are hidden from public view. In this case, there’d be no trace of the service directly on the customer’s website for BuiltWith to scrape.
• Retrieves the company’s general email address, but not their employees. Will require extra work to find employee’s emails if you want a higher chance of getting a reply.
• If you are not a SaaS company, you might not find this service useful.

How I use NerdyData to find competitors’ customers  

NerdyData is similar to BuiltWith. It crawls websites and looks at the source code to find your competitor’s embedded codes.

But NerdyData has slightly more comprehensive search capabilities than BuiltWith.

In BuiltWith, you can only find websites that use a certain tech. But in NerdyData, you have three search capabilities:

1. Find websites with all the tech
2. Find websites with any of these tech
3. Find websites with none of these tech

I searched Intercom on the first search bar. Another thing that separates NerdyData from BuiltWith is that NerdyData has information on when it last crawled the websites, which makes it easier to expect the freshness of the data.

However, compared to BuiltWith, NerdyData only found 79,519 websites while BuiltWith found 142,947 websites.

And guess what? I emailed NerdyData’s founder David Bielik about it too.

He said NerdyData is “more likely to give you accurate lists, even if it means excluding websites and having lower total volume.”

He continued, “With BuiltWith, we’ve heard from customers that they have to spend lots of time manually reviewing and filtering out inaccurate results.”

However, NerdyData lacks the contact details that BuiltWith provides, such as addresses, phone numbers, and the company’s email addresses.

But NerdyData's custom export is more user-friendly than BuiltWith. It took me a while to understand BuiltWith’s layout. I got NerdyData’s right away.

When you click on the green Download Website List button at the top right, this overlay appears.

In the Download Columns bar, you can select or deselect the columns based on your needs. When you click Download Report, you’ll be directed to the pricing page.

You only have 1 download for a free account. To get unlimited downloads, you need to upgrade to at least the basic plan which is $200 per month.

Here’s what the exported data looks like.

Pros of using NerdyData

• More comprehensive search capabilities than BuiltWith
• More accurate results
• Legal since NerdyData scrapes source code that is publicly available

Cons of using NerdyData

• Not enough contact details, unlike BuiltWith
• Not a useful method if your competitor is not a business that embeds their code on their customers’ websites
• If you are not a SaaS company, you might not find this service useful

3. Look for customer reviews on review websites

If your competitor is an established company, this is one of the most common approaches. Usually, they’d have received a lot of testimonials and case studies compared to startups or early-stage companies.

Why this method can help find competitors' customers

I used G2 and Featured Customers to find competitors’ customers. These tools make it easy to know who’s using (or has used) the product because the reviews and testimonials are either written by real users or shared by the company itself.

How I use Featured Customers to find competitors’ customers

Featured Customers is a platform for B2B software and services to showcase customer testimonials, case studies, and reviews.

Unlike BuiltWith and NerdyData, Featured Customers don’t rely on scraping websites.

Instead, it lets B2B companies list themselves on the site and add their testimonials, case studies, and reviews.

However, Featured Customers doesn’t provide customers’ email, social media, or phone numbers. You can only see the customers’ full names, titles, and company names. 

You’d have to manually look them up on LinkedIn, or you could use data enrichment tools to automate that for you.

You can immediately search for your competitor on Featured Customers. Just like other examples, let’s search for Intercom.

Now that you’re on Intercom’s reference page, you can see the company’s summary, reviews, case studies, and customer videos.

On the Testimonials, Case Studies, and Customer Videos page, you can filter them based on industry and company size. You’ll also get to know the customers’ full names, titles, and company names.

This way, it’s easier to find potential customers that meet your ideal customer profile (ICP).

Pros of using Featured Customers

• Can filter types of customers to meet your ICP.
• The data on Featured Customers is surely legal because B2B companies provide it themselves. This means that Featured Customers only show data and reviews that companies have given their consent for.

Cons of using Featured Customer

• No contact information provided.
• Have to manually search contact information on LinkedIn or other sources
• All testimonials are positive, since they are submitted by the companies themselves. So, they're most likely on good terms with your competitor.

How I use G2 to find competitors’ customers 

G2 is a B2B software and services review site. Unlike Featured Customers, which have customer testimonials, case studies, and reviews—G2 only focuses on customer reviews.

You can start by searching for your competitor. As usual, let’s search for Intercom.

Then, you’ll land on the product page where you can read about the product information, reviews, pricing, features, and implementation.

One thing that stands out for me is G2’s reviews.

They are much more structured and clearer about the software capabilities than Featured Customers. Every customer answers two important questions: What do you like and dislike about the software?

You can also filter reviews based on two or one-stars to poach unsatisfied customers.

Also, every customer has labels such as “Verified Current User” and “Validated Reviewer” to show the reviews are authentic and from a real person.

However, you’ll only get to know the customer’s name and title, not the company they work for. Using a separate data enrichment tool can resolve this issue.

The data on G2 are also surely legal because the reviews are all user-generated.

Pros of using G2

• You’re most likely getting an objective answer from a real user.
• Can filter reviews based on two or one-stars to poach unsatisfied customers

Cons of using G2

• You have to manually find the reviewer's contact information
• Some reviewers are anonymous

4. Search for competitors’ customers on Twitter/X

This is one of the most manual methods of them all, but it works best if your competitor is active on Twitter/X.

Why this method can help find competitors' customers

You can find your competitors’ customers by looking at their followers and comments. Usually, customers follow brand pages to stay up-to-date and leave comments to show support or complain about issues.

How I use social media to find competitors’ customers

Let’s search for Intercom on Twitter/X.

It has 43.4k followers. Among this sea of people must be their customers.

But how do you know which is a customer or not? They could be employees, ex-employees, or just random followers. Well... you can’t. Unless you manually cross-check LinkedIn or an employee directory, which would take forever.

So, let’s check the Replies tab. Then, you’ll see this interaction.

Now, it's highly possible that @thepremiumguy_ is Intercom’s customer. To contact him, click on the profile picture and find the DM button.

Okay, replies are tedious to get through. I get it. Let’s try another approach. This is where it gets easier. 

Some companies have dedicated customer support pages on social media. This can be an even more direct way to zero in on their customer base.

In Intercom’s Twitter/X bio, there’s a mention of @intercomsupport. After you click it, you’ll land on a new Twitter/X page specifically for customer support.

When you go to replies, you’ll see a lot of customer support requests. You’ve struck a potential goldmine here!

Now, to contact them, click on the profile picture and find the DM button.

However, if you don’t follow each other, your message will be sent to the request inbox instead of the main inbox. That means the chance for them to notice you might be low.

Pros of using social media to find competitors’ customers

• Easy to reach out.
• Easy to identify the customers’ pain points, which you can use to personalize your outreach.

Cons of using social media to find competitors’ customers

• Hard to differentiate whether the profile is an employee or a customer.
• DMs might not get noticed.

The problems with these methods

When you spy on your competitor's website or search on Featured Customers or G2, you won’t get the most important thing you need: the customers’ contact details such as email addresses.

While tools like BuiltWith or NerdyData can give you details like phone numbers, employees' LinkedIn profiles, and company email addresses of your competitors’ customers, they’re mostly limited to SaaS businesses that use code embedded on websites.

When looking through social media, it’s hard to differentiate whether a profile is a customer or not. Plus, even if you can separate them, sending DMs might not be the best option since they might not even notice.

So, if you're not a SaaS company, the previous methods may not be the most helpful. What if you’re an advertising or expense management company? How do you find your competitors’ customers and their relevant contact details?

5. Search using Sapiengraph’s Customer Prospector

Sapiengraph's Customer Prospector is a tool that lets you find your competitors' customers in any B2B industry—and get their email addresses instantly.

No matter what field your competitor is in, we’ll help you steal their customers. However, we can only find customers of B2B businesses, not B2C.

It’s also very easy to use, even a 7-year-old could do it.

How to use Sapiengraph to find competitors’ customers 

Once you’ve signed up for a free Sapiengraph account, you’ll see this dashboard. Click Prospector on the left sidebar. Then, click Customers on the top menu button.

Let’s pretend Intercom is your competitor, and search for them on Sapiengraph's Customer Prospector.

And there you have it! We've found Intercom's customers, along with their LinkedIn profiles, Twitter handles, and email addresses.

Quick note on emails: we'll do our best to find them, but if we can't, we'll clearly state None Found. Don't worry though - you can always reach out via LinkedIn or Twitter since you'll have those profiles."

Sapiengraph is credit-based. Good news - searching is totally free! You'll only use credits when you're ready to unlock specific profiles (30 credits each). Whether you want just one profile or all 398 results, you decide what to unlock.

On the free trial account, you can unlock up to 3 profiles.

To export, simply click the Export button on the top right.

How to use Sapiengraph to find employees' direct emails

As I've mentioned before, I prefer having an employee's direct email address. You'll actually get your message in front of the right person and it ups your chances of getting a reply. Skip the generic company inbox where emails go to die.

Let's say Capgemini is one of Intercom's customers. Now we want to find Capgemini's Marketing Manager to send them a cold email.

Easy, just go to the People Prospector.

Tick Has Email, use 'Capgemini' as the company’s name, and enter 'Marketing Manager' as the job title. Voila!

Sapiengraph is CCPA and GDPR-compliant, so you can charm your competitors' customers worry-free.

Pros of using Sapiengraph

• Finds likely customers of your competitors, no matter what field your competitor is in
• Include customers’ email addresses, LinkedIn and Twitter/X profiles
• Can find employees' email addresses in the same dashboard

Cons of using Sapiengraph

• For finding customers of B2B businesses only
• Our Customer Prospector is still experimental and doesn’t account for people who may have churned. See how our Customer Prospector work

What is Sapiengraph?

Now, it's time for a proper introduction.

I'm part of Sapiengraph. We're an advanced business intelligence tool and data provider. We have 3 growth tools that will get you productive in just 5-minutes. They are:

1. Prospector (Person, Companies, Customers) to instantly and easily build lead lists.
2. Data Enrichment Spreadsheets so you can enrich your leads’ data directly in your spreadsheets.
3. Job Change Monitor to track your key buyers' job changes

Check out sapiengraph.com to learn more.

Ready to steal your competitors’ customers?

In this guide, there are 5 ways you can use to easily and quickly find your competitors’ customers. 

They are by looking for customer testimonials on websites, using web profiling tools like Built With and NerdyData, checking review sites such as Featured Customers and G2, and lastly, searching using Sapiengraph’s Customers Prospector.

The choice is yours to decide which tools are the best for your business. 

Personally (and biasedly), I would recommend Sapiengraph. Not only does it find your competitors' customers, but you can also get enriched contact details, and track when they change jobs. Perfect for spotting new sales opportunities.

All that for just $49 per month.