Reddit Cohort

A Reddit cohort is a defined subset of Reddit users grouped by subreddit membership, interest, or behavior — used for targeting, monitoring, and audience research. Unlike demographic cohorts on other platforms (age, gender, location), Reddit cohorts are usually defined by topic: "users active in r/devops," "users who post in any of r/SaaS, r/startups, or r/Entrepreneur," or "users mentioning AI tools in the last 30 days."

For advertising, Reddit Ads exposes cohort targeting natively: you choose subreddits whose subscribers you want to reach, interest categories Reddit infers from posting behavior, and custom audiences built from your own data. Cohort selection is usually a stronger lever than creative iteration; getting the cohort right means even mediocre creative converts, while perfect creative aimed at the wrong cohort wastes spend.

For organic monitoring and research, cohorts are implicit but equally important. A B2B SaaS founder's relevant cohort is "users active in business and operations subreddits," not all of Reddit. The subreddit list that defines the cohort is the same one used for keyword-monitoring targeting — these decisions overlap in practice.

Defining a cohort well requires understanding where your audience actually congregates, which is rarely obvious from the outside. Customer interviews, support-ticket text analysis, and reading the subreddit activity of known customers are common methods. A founder whose customers all turn out to also be active in r/agencylife learns something useful both about positioning and about where to invest organic effort.

Cohorts evolve. A subreddit that's the right audience today might shift in two years as the community grows or as your product matures. Periodic review of which subreddits are producing relevant conversation (vs. just historical conversation) keeps the cohort definition current. RedNudge users tend to revisit their subreddit list every few months for this reason.