If you see someone that's good, you can put a bounty on them, so if someone with a bounty is in your lobby, and you tag them, you get like 20 butt coins (or the amount he/she offers), maybe the more people put a bounty on someone, the more he's worth, so 5 people is 100 butt coins, or something.
And depending on there skill, Wich you can maybe determine by what there average placement in a game is, by there average speed, on a scale 1 - 10 depending on that you might have to tag a lvl 3/10 you have to tag like 4 - 5 times, and if someone evades the bounty long enough, they can't log off or go to a private, or the timer will pause, if they evade the bounty then they get the butt coins.
ALso you could let people choose if people can put bounties on them, if no, then they won't get butt coins from that, but no one will get butt coins from them, or on, where you can get butt coins from them, but they can also get butt coins
I spent 3 hours writing this