Well there are quite a few sports betting ebooks out there on ClickBank, if you are willing to delve into that direction it could be a pretty big earner. Either way that is a rather compulsive advertising base so pick anything guys like and you can probably sell it pretty easily.
Well, so far I got rejected by eBay Partner Network. I have no idea why as I had easily gotten AdSense, Amazon and a few other affiliate accounts.
Have you considered using. A) Male Enhancement Ads. B) Ordering Pizza. C) Game Tickets D) Male Baldness ads E) Home Gyms/workout systems along with gym memberships. F) Fantasy Football G) Poker ads H) Electronic ads : HDTV,Bluray,Cell Phones etc. I ) Video Games/systems J) Trucks/Suv/Cars ads. As you know the idea is to target your audience. Which in this case I'm assuming its predominately males.
No. Some affiliate promotions allow for incentive traffic. This means you would offer to pay those who do free signups, try a product, etc, would get like 25% of what you earn from the signup. For example, say you get $1 for each signup, you'd pay your forum member $.25. Just an example and there are obviously much higher paying promotions out there. Would take a little setting up, but may be worth it.
I haven't got much experience in the sport's niche but definitely you have to choose an affiliate program that sells psychical products such as Amazon. For example you can sell soccer accessories and clothing, footballs and the like Digital products won't sell that well..