Not sure which behavior you mean, but for me it is the zap: a reader pays for a post and leaves a receipt instead of a like. You end up writing to be worth sats rather than worth clicks. Receipts only cover part of that picture though. In my own October count, roughly a third of the incoming sats ever showed up publicly on the relays I could query. The rest arrives unrecorded, so the visible reciprocity is a floor.