detailed online gaming industry data/information?

[graarrg]

I am hunting for some good sites with fairly reliable information about online gambling as an industry. Mostly, via google, I find lots of wishy-washy information on sites crammed with affiliate links.

Does anyone know of any scholarly research done on the topic? Even if it's just numeric data, it would help. Any sort of investment analysis or forecasting would be excellent as well.

There just isn't much literature on the topic (I found two books in my hunt, both related to legal issues).

Thanks a bunch.