We profile subreddits mechanically: rules text, moderation signals, what actually gets removed versus what survives. The corpus is past 2,100 communities now, growing as our users' niches pull new ones in.

Building that corpus taught us more about Reddit marketing than anything else we've done, and the headline numbers are blunt enough to reframe how you pick targets. Of the 1,915 communities we've successfully profiled:

101 (5.3%) clearly allow self-promotion.
799 (41.7%) allow it only with moderator permission.
172 (9%) ban it outright.
843 (44%) never say either way.

Sit with the first number. When a founder says "I'm going to market on Reddit," the mental model is usually "post about my product in the ten subreddits where my buyers hang out." The actual terrain: roughly 1 in 20 of those communities has clearly said yes to that. The most common explicit policy isn't yes or no; it's ask first. And the single largest bucket is silence.

"Unclear" is not permission

That 44% deserves its own section, because it's where founders make the expensive mistake.

A community whose rules don't mention self-promotion has not thereby allowed it. In practice, unclear-rules communities enforce norms through removals instead of rulebooks: the sidebar says nothing, and your product mention disappears anyway, silently, because the mods' working policy lives in their removal behavior rather than their rules text. Some unclear communities are genuinely relaxed. You find out which kind you're in the same way either way: read what survives, not what's written.

Sort the community by top posts this month. Are any of them written by builders about their own products? Did those authors disclose? What ratio of story to pitch did the survivors strike? Five minutes of this tells you the real policy more reliably than the rules page, because it shows you enforcement, not legislation.

Links are gated even harder

Self-promotion policy is about whether you may talk about your product. Link policy is about whether you may point anywhere at all, and it's stricter than most founders expect. In the same profiled corpus:

176 communities (9.2%) prohibit links in posts or comments outright.
60 more allow only specific anchors (official docs, papers, no commercial domains).
Only 534 (27.9%) clearly permit links.
The rest, again, never say.

This is why the most consistent removal trigger we see is not "mentioned a product." It's "included a URL." A comment that names your product plainly ("we build X, it does Y") frequently survives where the same comment with a link dies at the AutoMod layer, because URL-plus-young-account is one of the most common automated removal rules on the platform. The next post (the reply that survives) builds on exactly this fact.

How to profile a community by hand

Our system does this automatically, but the manual version is twenty minutes well spent per target community, and the checklist is short:

Rules and wiki, obviously, but read for thresholds. Minimum account age, minimum karma (sitewide or community), "no links," flair requirements, dedicated promo threads. These are AutoMod's published half; treat every threshold as real. And know how small that published half is: in our corpus, only about 2% of communities mention karma anywhere in their public rules, yet karma gates fire constantly, because most live in unpublished AutoMod config. Where rules do name a karma type, comment karma outnumbers post karma 11 to 2, so the standing that opens doors is built in comment sections, not link submissions.
The removal record. Sort by new, open a dozen threads, look for [removed] patterns. Which kinds of comments are dying? If builder comments with disclosure are surviving, that's your real policy signal.
Promo days and designated threads. A meaningful slice of the ask-first communities concentrate promotion into scheduled threads ("Self-promo Saturday," "What are you building?" weeklies). These are the sanctioned front door, and founders routinely miss that they exist.
Mod activity level. A community with visibly active mods (regular sticky posts, fast removal of junk) is safer for the honest operator, not more dangerous: enforcement is predictable and asking permission actually reaches a human. Dead-mod communities are where norms are enforced by mass-report instead, which is far less forgiving.
The dominant format. Every community rewards a shape: long story posts in one, terse data posts in another, questions in a third. Your contribution should arrive in the local format. This is also the strongest argument against cross-posting the same text everywhere; format mismatch reads as tourist instantly.

Ask-first is a real channel, not a rejection

The 42% mod-permission bucket looks like friction. Treated properly, it's an asset. A short, honest modmail ("I build X, this thread asks about exactly that problem, may I answer with a disclosure?") gets ignored sometimes, but a yes from a mod is close to a safe-conduct pass: you are now the founder who asked, in a community where your competitors either stayed silent or got removed. The ask costs two minutes. Founders skip it because it feels like asking permission to market. It is. That's the point. Permission is cheap and removals are expensive.

The honest read: target selection is where Reddit GTM is actually won, before a word is written. The instinct-driven version ("the big subreddit in my space") walks straight into the 9% ban bucket or the silent 44% with no map. The mechanical version (profile first, then choose the communities whose policy, format, and mod posture you can actually work with) is slower for a day and faster forever after. Most of your competitors will never do it, which we mean as encouragement.

Thread Otter runs this profiling continuously: every target community gets rules classification, link policy, format read, and our own survival statistics, and the send pipeline enforces the result (a promo-banned community simply never receives a promotional draft). If you'd rather run it by hand, the checklist above is the whole method.

This is post 4 of the 8-part Reddit for founders series. Next up: the reply that survives, or how to be useful, disclosed, and unremoved in the same comment.