Realistically, this likely won't piss off their userbase nearly as much as the API fiasco last summer. A significant amount of users stayed in light of a number of subs going dark, so I have a feeling an influx in ads won't really grind too many gears (or they will but will just bitch and nothing more).

Reddit is much more mainstream these days, and your average Melvin is just used to ads at this point.

"If your username was a username, how username would username username?"

They're here.