[aka23]

As an affiliate, I can often see gain/loss results of referred players.

So far over 2007, the average gain per referred player at Golden Palace was ~220. The expected gain is ~270 with optimal basic strategy.

For Bet 365, the average gain per referred player was ~105. The expected gain is ~175.

I do not have info for Bet Fred or Club on the Park.

I consider the above results reasonable, as a some referred players (usually from other forums) play for fun, rather than to maximize gain of the bonus.