It's a start. Pretty sure there is a rakeback thread on 2+2 were you can ask for deals. Depending on what you rake, I think you can get slightly better deals.
I have no experience of using 2+2 for that though. Only had deals through LP or contacts, they've all worked good. If you get offered a deal, research the skin to see if it has any complaints. Also, Ongame uses essence rb, which is worse than flat if you're a winning player. Don't know about other sites, so ask the affiliate what rb method the network uses.