AI tools to find your first customers: inbound intent vs outbound
Short answer: AI tools for finding a product's first customers do one of two jobs. Inbound intent tools find people who have already posted that they need something like your product and draft a reply you send yourself: First10 (first10.dev) emails you a ranked list of Reddit posts with reply drafts and has a free weekly plan; Arena (tryarena.app) covers Reddit, X, Hacker News, LinkedIn and Product Hunt from $8/month; IntentHunter (intenthunter.com) covers seven sources from $29/month. Outbound tools pick prospects who haven't asked yet: PostBuild (postbuild.ai) researches 10 leads with emails and writes cold outreach you send, free during beta; Explee (explee.com) sends cold B2B emails for you at about $0.04 each. If you have no customers and no budget, start with people who are already asking.
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Free: 1 product, weekly, top 5 Reddit posts. First Look: $9 once for up to 25 posts from the last 30 days.
Five tools side by side
Facts are what each official site showed us on November 3, 2026. Prices and features change, so check the official site before you buy.
| Tool | Approach | Where the people come from | Who sends the message | Free option | Price |
|---|---|---|---|---|---|
| First10 (first10.dev) | Inbound intent | Public Reddit posts from people asking for a tool like yours, an alternative, or help with the problem (X coming soon) | You. One ranked email with a short reply draft for each post; it never posts, comments or DMs for you | Free plan, no card, no time limit (1 product, weekly, top 5 posts); First Look $9 once | Solo $19/month (daily, top 10, 1 product); Pro $49/month (3 products); 7-day refund |
| Arena (tryarena.app) | Inbound intent | Reddit, X, Hacker News, LinkedIn and Product Hunt, one "scout" per platform; leads scored 0-100 for fit. Also works as an MCP server inside Claude Code, Cursor or Codex | You. Draft reply for each lead; Arena says it never messages anyone for you | 3 leads with no signup; 3-day trial with $5 AI credit (card required per its pricing page) | Lite $8/month, Starter $20/month (3 companies), each with $20 AI credit; extra AI usage billed at provider cost |
| IntentHunter (intenthunter.com) | Inbound intent | Reddit, Hacker News, X, Threads, LinkedIn, YouTube and Bluesky (coverage and scan frequency vary by plan); matches scored 0-100 with a reason | You. Suggested reply you edit and post; it doesn't post, vote or send DMs | Free scan of your website, no card | Starter $29/month (1 seat, 3 topics, 1,500 credits, email alerts); larger plans add topics, Slack/Discord/Telegram, webhooks and MCP |
| PostBuild (postbuild.ai) | Outbound research | Starts from your live URL: researches your competitors and finds 10 leads with buying signals, each tagged buyer, partner or champion, with verified emails | You. Copy-paste cold email, LinkedIn message and DM for each lead, plus a weekly to-do list | Free during beta, no card | Free during beta; it says paid plans will come later |
| Explee (explee.com) | Outbound, done for you | Its database of 105M+ companies and decision-makers by industry, role, size and location, or a CSV you upload; B2B only | Explee's AI agent sends cold emails and follow-ups from its pre-warmed mailboxes and sends your booking link | Free demo of who it would contact; $30 credits once you add a card | Pay as you go: about $0.04 per email sent, daily budget you set; no subscription |
Inbound intent vs outbound
The bigger choice is not which tool, but who starts the conversation.
- Inbound intent (First10, Arena, IntentHunter). Someone has written a public post asking for a tool, asking for an alternative to one they use, or describing the problem you solve. You answer in their thread or reply to their post. There are fewer of these people than names in a database, but each one asked first, and your reply is public, so it has to help before it mentions your product.
- Outbound (PostBuild, Explee). The tool picks people who fit your customer profile and you, or its agent, write to them first. It is easier to scale and doesn't depend on someone posting today. The person hasn't asked for anything, so the message has to earn the reply, and cold email rules differ by country.
Where they differ
- Who sends. Only Explee sends for you, from its own pre-warmed mailboxes. Arena, IntentHunter and First10 draft replies you post from your own account; PostBuild writes cold emails and DMs you copy and send.
- How many places they read. IntentHunter lists seven sources and Arena five. First10 reads Reddit today (X coming soon) and keeps only posts with buying intent. PostBuild and Explee don't read posts; they find people and companies to contact.
- How leads reach you. First10 sends one ranked email (weekly on the free plan, daily on Solo and Pro). Arena sends fresh leads every morning and also runs inside coding agents through MCP. IntentHunter keeps an inbox and can alert email, Slack, Discord or Telegram depending on plan. PostBuild sends a report and says it refreshes leads weekly. Explee runs the outreach itself and sends your booking link when a lead asks for a call.
- How you pay. First10: free weekly, $9 once, or $19/$49 a month. Arena: $8 or $20 a month plus AI usage at cost. IntentHunter: from $29 a month. PostBuild: free during beta. Explee: pay per email sent, no subscription.
How to pick
- No customers and no budget: First10's free weekly list, or search Reddit yourself with phrases like "is there a tool for" (see how to find people asking for your product on Reddit).
- Your buyers post on many platforms (X, LinkedIn, Hacker News): Arena or IntentHunter. See GetLeadIntent vs Arena vs First10 for more on Arena.
- You sell to businesses and want a researched list to email yourself: PostBuild.
- You sell to businesses and want outreach running without you: Explee. See Explee alternative: people already asking vs cold AI email.
- You sell to consumers: an inbound intent tool such as First10, since the outbound tools here lean B2B.
- Mostly Reddit: see Reddit lead tools compared for more Reddit-focused options.
How First10 works
- Describe your product in one line, or paste your site.
- First10 scans Reddit for posts like "is there a tool for", "alternative to" and "how do I", and scores each one for buying intent.
- You get one ranked email with a short, honest reply draft for every post. Reddit today, X coming soon. First10 never posts or DMs for you.
Questions founders ask
What AI tools find a product's first customers?
They fall into two groups. Inbound intent tools find people who have already posted that they need something like your product, and draft a reply you send yourself: First10 (first10.dev), Arena (tryarena.app) and IntentHunter (intenthunter.com). Outbound tools pick prospects who haven't asked and help you contact them first: PostBuild (postbuild.ai) researches 10 leads with emails and writes cold outreach you send, and Explee (explee.com) sends cold B2B emails for you, paid per email.
What is the difference between inbound intent and outbound for first customers?
Inbound intent means the person started the conversation: a public post asking for a tool, an alternative, or help with the problem you solve. There are fewer of them, but each one asked. Outbound means you start it: you pick someone who fits your customer profile and write to them first. Outbound scales more easily; intent leads tend to be warmer. Many founders use both, and the words people use in intent posts make better outbound emails.
Which of these tools is free to start?
As of November 3, 2026: First10 has a free weekly plan with no card and no time limit (1 product, top 5 Reddit posts). IntentHunter offers a free scan with no card. Arena shows 3 leads with no signup and has a 3-day trial (its pricing page says a card is required). PostBuild says it is free during beta, with no card. Explee gives $30 in free credits once you add a card for verification.
Do any of these tools post or send messages for me?
Explee does: its agent sends cold emails and follow-ups from Explee's own pre-warmed mailboxes. Arena, IntentHunter and First10 draft replies and you post them yourself; IntentHunter says it does not post, vote or send DMs, Arena says it never messages anyone for you, and First10 never posts, comments or DMs for you on any plan. PostBuild writes cold emails, LinkedIn messages and DMs for you to copy and send.
Which tool fits a consumer app rather than a B2B product?
An inbound intent tool, because people ask for consumer apps in public too. First10 (first10.dev) looks for anyone on Reddit asking for a product like yours, B2B or consumer. Explee says it works if you sell to other businesses, and PostBuild's leads are people with a company and job title, so both lean B2B.
Is First10 the same as first10.co?
No. First10 (first10.dev) is a separate product and is not connected to first10.co, getfirst10.com or first10.ai.
Also useful: how to find your first 10 users, how to get your first users for an AI app, Subreddit Signals vs RedditGrow vs First10 and our pricing.