Your "cake day" is the anniversary of the day you joined a site. These are well known from Reddit, but are support in other software, or from mods.

My experience, mostly from Reddit, is that cake days do nothing but generate noise - with potentially several people posting off-topic replies saying "happy cake day" and then the person who's cake day it is saying "thanks". This noise usually doesn't get deleted either, so, a day, a week, or months later those posts will still be there.

I assume that some people must get a momentary buzz from getting congratulated for registering some number of years ago, but it's not like it's a birthday. The downsides seem to be to strongly outweigh any slight benefit.

Does anyone have experience from a community they run where they've been able to turn cake days into a net positive, where it doesn't just produce noise, and where it's actually a meaningful date for the members, one they actually remember and anticipate before it arrives?