List of subreddits and their self-promotion days/weeks?

Hi all,

I've been doing some content marketing and subtle shilling in subreddits that are related to ecommerce and small businesses. A lot of these have rules against self promotion and they're pretty strictly enforced - some like /r/EtsySellers and /r/smallbusiness have designated weekly threads where promotion is allowed, and I've seen a decent amount of traffic from these.

Does anyone have a list of places, either on Reddit or other forums, where this type of "promote yourself here and you won't get banned" channel exists? If not, we could come together and try to compile one!