belgamo, I have not used this yet myself as advertiser but have ads from this company running in replacement of Text ads – AdBright.
They do accept gambling sites and you can place test ads, basically you buy a 7 days guaranteed link, a 30 days, PPC as well as few other options …
You can see example on my site, but please Note: I have not used it as advertiser only as publisher. So I don’t know what results to expect. Another company that accepts gambling PPC ads that I know of is Bidvertiser, but once again used them only as publisher …
Have a look at those companies, perhaps it will answer your questions …