User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-43826407-20210119102940/@comment-1807002-20210119175334

I think it was something along the lines of judging users by join date or first edit date. But if we really want to find out we can stalk their edits but that is creepy and tedious. I am sorry but I do judge users based on join date + edit count (12 edits + join date over a year = mostly lurker or casual visitor, 1,000 edits + join date over three months = medium active, etc.), it is a quick and dirty way to size up an editor without going indepth stalker mode.

I dunno watching people play basketball isn't exactly joining the team but the first day you play with them—is joining them—even if it is casual, rare or daily (or a one off). Watching isn't committing, so who cares the day you starting watching anyways.