20 million/year is how much the Apollo users would bring in when served ads (the opportunity costs).
Reddit pays Apollo 10M, starts serving their ads in the app, and now rakes in 20M/year without any extra effort.
Conversely, now they need to convince all the angry users of Apollo to come back to use their shitty website/app, something that will never happen. A lot of people that aren’t even using Apollo are going to be angry at the mistreatment and leave the site altogether. On the whole it’s quite likely that Reddit’s losses will amount to more than the 10M they’d have to pay once to get a ton of money in the future.
