SignalPlay: How We Automated Reddit to Generate B2B Leads | Karhuno AI Blog
Automation recipesUpdated October 2025 • 6 min read

SignalPlay: How We Automated Reddit to Generate B2B Leads (Without Being Spammy)

A step-by-step guide to building a Reddit commenting engine using n8n + GPT + Supabase — for fully automated, high-quality inbound.

KA

Karhuno AI Team

Published October 2025

Reddit automation workflow with n8n and GPT for B2B lead generation

What Is SignalPlay?

SignalPlay is our custom-built Reddit Autocomment Engine — a fully automated workflow that monitors Reddit conversations in real time, filters for high-intent posts, uses GPT-4o to craft human-like replies, and publishes them instantly.

It started as a weekend experiment using n8n, Supabase and GPT, and quickly became one of our highest-performing inbound growth channels.

Today, over 20 people contact us daily after seeing our helpful replies on Reddit.

All without ads. Without links. Without sounding like salespeople.

How the Automation Works (Step-by-Step)

1. Trigger & Post Discovery

The workflow runs every few minutes and scrapes fresh posts from subreddits like:

  • r/LeadGeneration
  • r/SaaS
  • r/Entrepreneur
  • r/startups

It looks for hot posts containing keywords like:

  • "lead gen tool"
  • "replace Clay"
  • "cold outreach problem"

2. Deduplication with Supabase

Each post is checked against Supabase. If it's already been processed, the workflow skips it.

3. Quality Filter

Only posts that meet these conditions are considered:

  • More than 2 upvotes
  • Text content is present
  • Created within the last 6 months

4. GPT Screening – Step 1

GPT-4o analyzes the post and answers:

"Is this a real business pain point related to sales, lead gen, or B2B growth?"

Only posts with a "yes" continue.

5. Key Data Extraction

We extract all relevant metadata: post text, upvotes, subreddit size, creation date, and direct link.

6. GPT Comment Creation – Step 2

A second GPT prompt generates a natural, empathetic reply — never salesy, never spammy.

Example comment:

"Had the same problem recently. Ended up testing a signal-based tool that tracked funding and hiring. Let me know if you want to see what worked for us — happy to share."

7. Comment Is Posted

The reply is posted automatically to the original Reddit thread — no links, no hard CTA.

8. Logging + Human-like Wait

  • The post is logged to Supabase
  • The system waits 60–300 seconds before processing the next post (to mimic real behavior)

Get the Complete n8n Workflow

Download the full SignalPlay automation workflow and import it directly into your n8n instance. Includes all 8 steps, GPT prompts, and Supabase integration.

Download n8n Workflow (JSON)

Free • Ready to import • No signup required

What you'll need to run this workflow:

  • n8n instance (self-hosted or cloud)
  • OpenAI API key (for GPT-4o)
  • Supabase account (free tier works)
  • Reddit API credentials (free developer account)

Built-In Safeguards

✓ Double filtering (logic + GPT)

✓ History tracking via Supabase

✓ Randomized delays

✓ Human-style tone + prompt design

Best Use Cases

  • Startup or side project promotion
  • Silent market validation
  • Community-based lead generation
  • Early traction without paid ads

Why Reddit Works for B2B Leads

Reddit is one of the most underrated lead generation platforms.

Here's why:

  • 1.8B monthly visits
  • 430M active users, many in professional roles
  • 78% make purchasing decisions at work (Reddit Internal Data)
  • 100,000+ active communities across SaaS, AI, logistics, fintech, HR, and more

The Real Power of Reddit

Reddit is where:

  • Buyers ask for help before Googling
  • Founders share unfiltered pain points
  • Marketers, consultants, and PMs post real problems, looking for advice

These are live buying signals — if you intercept them in the right way, they become warm leads.

Real Example

Post on r/Entrepreneur:

"Struggling to get traction for our B2B SaaS. Anyone found a good lead gen strategy?"

You reply with empathy

You share your experience (not your pitch)

They check your profile → land on Karhuno → book a demo

This is not advertising. It's smart presence.

Ready to automate your lead generation?

Start tracking buying signals across Reddit, LinkedIn, and the web.