Hey Fonzi BTW,
yes i noticed for a while poker/casino sites doing that.
They redirect your affiliate link with a 301 redirect
So you link to pokersite.com/aff12345 it then redirects that to pokersite.com and google then treats that as a backlink to pokersite.com
So everyone who just uses normal links to poker/casino sites without doing an internal redirect first (which alot of affiliates do for click tracking), you are giving VERY valueable backlinks to the casino/poker sites.
I noticed this a while ago when checking bodogs HOMEPAGE backlinks and i found my site in there, yet i dont link to there homepage and then realised that because they always redirect the affiliate link to there homepage(which makes the url look better for the visitor), google treates it as a backlink.
Overtime this will make all the poker rooms unstopable in the SERPS, it almost is now, i think 8 or 9 out of top ten for terms “poker” or “online poker” are actual poker sites.