Have crossfire option specifically for people who are teamed up in clans. Also have it set so that clans can have their own personal home arena as well as a choice of symbol and color scheme for their character outfits. Also have a choice of whether to play a ranked or scrimmage match. Later on set it so that clans can spectate their clan matches or other players can spectate the ranked matches. Create a ladder showing the top guilds during off season and during certain times of the year (aka season) take top clans and enter them into a playoff tournament. Winners of the tournaments receive prizes, bragging rights and/or exclusive downloadable content for their outfits.