How about a Barter network? So for instance one of these rich kids that have 6 Bulgasari and 8 Kumiho can trade with someone that won something that they already have. Or you want two Orkins that are not upgraded but you have a Trebuchet that is. It can completely volunteer and you have to list what you are willing to trade before searching. It would give someone the opportunity to use a robot that they can't afford, but still keeping them playing. So they don't quit playing, and eventually spend to arm that new robot! Or Pixonic can charge a small fee to join the Barter network.