I spent a month building a tool that reads Reddit/HN forstartup ideas — here's what "real pain" actually looks like

Spent the last month building a tool that surfaces startup
opportunities from Reddit, Hacker News, and X discussions. Solo,
bootstrapped, no team. More data sources on the roadmap —
including user-submitted ones (drop in a CSV of your own
support tickets, for example).

I expected the hard part to be the AI. It wasn't. The hard part
was figuring out which complaints online are actual paying
problems, and which are just people venting into the void.

Four things that surprised me:

1. Pain ≠ demand. Threads where everyone angrily agrees "someone
   should build X" almost never convert. Real demand sounds smaller
   and more specific — "I currently use Notion + 3 spreadsheets and
   it breaks every Tuesday" is a buyable problem. "Why is no one
   solving X!" is not.

2. The best signals hide in boring subreddits. r/SaaS and
   r/Entrepreneur are crowded and contaminated with "I'm building"
   posts. Niche subs like r/MedicalCoding, r/SmallFarms, and Etsy
   seller communities have 10x less noise and 10x more specific
   workflow language.

3. HN, Reddit, and X surface very different signals. HN is great
   for technical feasibility and early-adopter behavior. Reddit has
   the most raw emotional language. X is mostly noise unless you
   already know who to follow.

4. AI is surprisingly bad at distinguishing "rant" from "need"
   out of the box. A generic "summarize this thread" prompt will
   tell you every thread is a goldmine. I had to build explicit
   scoring for pain signal, demand signal, and willingness-to-pay
   before outputs got useful.

What I built: a platform called MonetScope (free beta right
now). It scores opportunities across pain / urgency / market
size / execution difficulty, and each opportunity comes with the
actual Reddit quotes that sparked it, plus a rough MVP plan.
Still 20 things to fix.

Where I am: a small batch of early users, honest feedback is
what I want most right now — not traffic.

Genuine question for the room: what's the worst "validated idea"
you ever built — one where the online discussion looked like
obvious demand, but the market turned out to be hollow? Trying
to get better at spotting that specific trap.