# How to Build a Lead List With AI: Map Your Market | PumpGTM Canonical URL: https://pumpgtm.com/blog/how-to-build-a-lead-list-with-ai [← All guides](/blog) Lead generation AI for GTM # How to build a lead list with AI: map your entire market from your competitors' customers To build a lead list with AI, start from your competitors' public customers, find look-alike companies, then the buyers inside them. The 5 steps, with prompts. Namanyay Goel · October 11, 2026 · 8 min read On this page - [Why most lead lists are wrong](#why-most-lead-lists-are-wrong) - [Step 1: List your 10 closest competitors](#step-1-list-your-10-closest-competitors) - [Step 2: Mine their testimonials and case studies](#step-2-mine-their-testimonials-and-case-studies) - [Step 3: Find look-alike companies](#step-3-find-look-alike-companies) - [Step 4: Find the buyers inside each company](#step-4-find-the-buyers-inside-each-company) - [Step 5: Message them](#step-5-message-them) - [One more source: your competitors' comment sections](#one-more-source-your-competitors-comment-sections) - [Questions founders ask](#questions-founders-ask) To build a lead list with AI, start from data that is already public: your competitors' customers. Ask Claude or ChatGPT for your 10 closest competitors, mine their testimonials and case studies for the companies that already buy from them, expand that into look-alike companies, find the buyers inside each one, then message them on LinkedIn, email and X. Those five steps map your entire market, and they are the same ones the 25 YC-backed startups using [PumpGTM](/) run. ## Why most lead lists are wrong There are a lot of services that will sell you a lead list. Most of them hand you a big export filtered by industry and headcount, and most of the people on it have never had the problem you solve. The most important thing is correct data. The best correct data you can get for free is your competitors' public information about their own customers: if a company pays your competitor, it has the problem, the budget, and a habit of buying tools like yours. ## Step 1: List your 10 closest competitors Point your favorite AI at it. In Claude or ChatGPT: List my 10 closest competitors. My product: [one sentence]. For each one, give the website and who it sells to. Don't stop at the list. It's the starting point, not the lead list. ## Step 2: Mine their testimonials and case studies Every competitor publishes who buys from them: testimonials, case studies, logo walls, customer stories. Ask your AI tool to go through each competitor's site and pull out an exact list of the companies, people and accounts named there. For each of these 10 competitors, find every company named in their testimonials, case studies and customer logos. Return company, website, and the person quoted if there is one. This gives you a list of companies that already buy what you sell. ## Step 3: Find look-alike companies Your competitors' customers are a sample of your market, not all of it. Use AI to expand the list into look-alikes: companies with the same size, industry and stack that are desperate for a solution like yours but are not on any logo wall yet. Here are 40 companies that buy [category] tools. Find 200 similar companies: same industry, size and business model. Return company and website. ## Step 4: Find the buyers inside each company A company does not reply to a message, a person does. For every company on the list, find the job titles who would buy (the VP of Sales, the head of growth, the founder) and get their work email, LinkedIn profile and X account. Tools like Apollo, Exa or PumpGTM do this. In PumpGTM you give it the companies and the titles, it finds the people, and it [scores each one before anyone gets a message](/blog/linkedin-lead-scoring-before-outreach), so the list stays small and right. If you want the scoring logic, it is in [why a lead is fit, timing, intent and confidence](/blog/gtm-engineering-lead-scoring). If you have done this properly, you now have hundreds of companies and maybe thousands of people who are the ideal buyers for what you sell. ## Step 5: Message them All that is left is using the data. An outbound tool connects your LinkedIn, email inboxes and X, and sends everyone a first message plus follow-ups until they reply. There are a lot of these tools, so do your own research. If you live inside Claude or ChatGPT like I do, PumpGTM runs the whole thing from your AI chat ([one prompt to find leads and book demos](/blog/ai-sdr-agent-one-prompt-book-demos)). The [LinkedIn and email play](/plays/linkedin-email) runs the sequence from your own accounts, [safely](/blog/is-linkedin-automation-safe-pumpgtm-account-protection), and [this is how the follow-ups work across channels](/blog/multi-channel-outbound-next-10-customers). ## One more source: your competitors' comment sections Customers are the strongest signal, but they are not the only public one. People who comment on your competitors' LinkedIn posts are thinking about the problem right now. [Your competitor's comment section is a lead list](/blog/research-competitor-comments-for-buyer-intent) shows how to use it. ## Transcript I'm Namanyay, I'm the founder of a Y Combinator-backed company, and I'm going to teach you how to map your entire market using AI. And these are the same techniques that 25 Y Combinator-backed companies use. So in the next three minutes, I'm going to teach you how to get real public data from all your competitors, use it to make a list of your entire target market, and start messaging them using the best GTM outbound machine. You know, there's a lot of bullshit services that tell you how to build your lead list, but the most important thing is to get correct data. And one way we can do that is to rely on your competitors' public information about their customers. So go ahead, point your favorite AI or Claude or ChatGPT and ask it to make a list of 10 competitors. But we're not going to stop there. And what we're going to do with our competitor list is to get our AI tool to find out all of their testimonials, case studies, and find out an exact list of companies, people, and accounts that buy from these competitors. Once you have the competitor account list we can use ai to find out a look-alike list and identify the best similar companies that are desperate for solutions like yours and now we're going to use this list of look-alike companies which were the companies that are desperate for solutions like ours and make a list of leads or people inside it who will be the final buyers and to do that we need to use some third-party tools apollo xr or PumpGTM are good ones and essentially you use these tool to find out the correct job titles and people and employees inside this company and get their email addresses linkedin phone numbers and twitter account if you've done this properly you now have a list of hundreds of companies and maybe thousands of people who are the ideal buyers for your solution all that is left is the final step of actually using this data and messaging and the thing you're looking to do that are called gtm outbound tools what these tools do is they connect your LinkedIn email inboxes and allow you to send outgoing messages to a given list of customers. And there's a lot of these tools on the market, so I encourage you to do your own research. But if you, like me, also live inside Claude or ChatGPT and want to run your entire GTM operations right inside your favorite AI, you need to check out pumpgtm.com. So pumpgtm or your outbound tool of your choice should allow you to connect all of your lead lists to your inboxes and start sending them outgoing messages. You need to send everyone an initial message and multiple follow-up messages. And I've covered that in a separate video. But hopefully this was useful to start making a proper data-backed lead list and doing outreach using the best AI tools like companies in San Francisco. Have you used any GTM tools in the past or have questions about your GTM strategy? Tell me about it in your comments and I'll try and help you out. ## Questions founders ask How do I build a lead list with AI? Start from your competitors' public customers. Ask Claude or ChatGPT for your 10 closest competitors, pull the companies named in their testimonials and case studies, expand that into look-alike companies, then find the buyers inside each one with a tool like Apollo, Exa or PumpGTM. What is the best data source for a B2B lead list? Your competitors' own customers. They already have the problem, the budget and a habit of buying tools like yours, and the list is public on their websites. How do I find look-alike companies with AI? Give an AI tool the companies that already buy from your competitors and ask for similar companies by industry, size and business model. Then check the list before you message anyone. Which tools find the email and LinkedIn of the right people? Apollo, Exa and PumpGTM all find people by company and job title. PumpGTM also scores each person and runs the outreach on LinkedIn, email and X. Can I do all of this inside ChatGPT or Claude? Steps 1 to 3 work in any AI chat. For steps 4 and 5, PumpGTM connects to Claude and ChatGPT so you can find the buyers and message them from the same chat. How do I message the list without getting my LinkedIn banned? Run it from your own account with a fixed IP, a slow warm-up and human pacing. Here is [how to automate LinkedIn safely](/blog/is-linkedin-automation-safe-pumpgtm-account-protection). [Namanyay Goel](https://nmn.gl/) · Founder, PumpGTM Founder of PumpGTM (YC). Writes about founder-led GTM, LinkedIn outbound, and the systems behind it. [X](https://x.com/NamanyayG)[LinkedIn](https://www.linkedin.com/in/namanyayg/) On this page - [Why most lead lists are wrong](#why-most-lead-lists-are-wrong) - [Step 1: List your 10 closest competitors](#step-1-list-your-10-closest-competitors) - [Step 2: Mine their testimonials and case studies](#step-2-mine-their-testimonials-and-case-studies) - [Step 3: Find look-alike companies](#step-3-find-look-alike-companies) - [Step 4: Find the buyers inside each company](#step-4-find-the-buyers-inside-each-company) - [Step 5: Message them](#step-5-message-them) - [One more source: your competitors' comment sections](#one-more-source-your-competitors-comment-sections) - [Questions founders ask](#questions-founders-ask) Share Founders doing this with PumpGTM [Supermemory Supermemory put founder-led LinkedIn outreach on autopilot](/customers/supermemory)[Docmost Docmost follows up with trial signups and abandoned checkouts on LinkedIn](/customers/docmost)[Browzer Browzer reaches DevRel leaders with outreach that reads like Rahul wrote it](/customers/browzer) ## Find and engage with buyers across channels Give your AI the super strength to find you leads and message them till you get the sale across LinkedIn, email, X, and more. ## More guides [### AI SDR agent: find leads and book demos from one chat prompt One chat prompt in Claude or ChatGPT: PumpGTM reads your site, picks buyers, finds who shows signals and messages them on LinkedIn, X and email. 6 min read](/blog/ai-sdr-agent-one-prompt-book-demos)[### How to sell to developers and engineers on X (the GTM channel nobody uses) If you sell to CEOs, engineers or developers, the most underrated outbound channel in 2026 is X. That is where they are, and almost no one runs it properly. Here is how to do it from your own account. 4 min read](/blog/sell-to-developers-and-engineers-on-x)