Investment is not possible at the moment (altough the feature is ready to roll out). I've thought a lot about it but there are still some uncleared issues about conditions and side effects. For example many people point out that a 35% comission would be too high compared to competitors whereas I think any lower percentage wouldn't be worth it (as long as you don't have an insane volume such as JD).
Investment will makes your site's bankroll bigger and that could attract more player if you got larger max profit so that could boost your volume to be higher. 10% is standard around here but there is no rules on how many you could take as the aite's admin, even betking takes half of house edge