Forums and games really won't get to all players.
Being able to advertise just for certain groups (win-rate, boot-rate, level, account age, maybe even based on in-game settings) would be very useful. I am not talking only about clans. I am sure some people would love to advertise events like MTL or CL.
According to
https://blog.taboola.com/how-much-do-websites-make-from-ads/, you get ~0.01 cents per view. So something like 10 views on the targeted audience/ coin seems like a very good prize for Fizzer.