trolling: you win spammer reward for 17 posts of same contents
and mods get consistency reward for 17 same answers 
anyhow, the model of direct rakeback seems to be dying for us players, as rooms prefer to mask the actual amount behind wicked deposit bonus/cash prize schemes. Not hard to guess why. To make things more complicated different sites on same network often have different values, which change, so meh..
For instance Carbon, which is Merge network has 5 loyalty tiers and they award:
Earth.......6% (Rake required per month = $25)
Wind.......7.5% (Rake required per month = $200)
Fire........10% (Rake required per month = $500)
Water.....15% (Rake required per month = $1000)
Ether......35% (Rake required per month = $2500)
(Info highjacked from a post by sun123 on a different forum, so all props to him).
So basically, unless you are a high-volume player with 1k+ rake you are stuck with 10-20% "rakeback" in most places. So rather focus on how comfy the software is for your needs, fishiness, tournament tickets, GTD pools etc.
In the poker room list there are several rooms (poker heaven, PKR, cake) for which PS still offers direct rakeback, so do check them out. http://www.pokerstrategy.com/online-poker-rooms/
Then a couple sites have a "loyalty bonus" thingie, where you get special dollars to spend on tournament buyins and whatnot depending on sites (Unibet, Ladbrokes).
If anyone manages to put together a comprehensive table with Point2rake calculation across all sites, I'm sure he/she could really get in some sweet traffic to their site. Damn, I should be doing it instead of typing this.. 
Hope this makes sense
cheers!
duba