Andrew-
Goodluck with your search for a good PPC engine. It seems that every week there are 500 more being added to the game. Most of them are run by former traffic affilates that use pop-unders & pop-ups to generate hits to the engine, or auto-searches. Almost all of the small ones depend on affiliates and small partnerships as well, so you’re really not paying for “search engine branded” traffic, you’re paying for “oh I’m here so I may as well search” traffic. Usually, I don’t recommend this, but since the casino industry is so cut throat when it comes to traffic and competition, I’d tell you to hire an SEO firm and just get natural rankings, if you don’t know how to do it on your own. Reason for this, sure, you’ll end up with smaller keywords, but it may give you an edge by gaining top rankings for 100’s of smaller keywords without having to worry about the quality of the surfer, or paying for each one!