I did a write up of 0% house edge gambling and how it will be profitable

"a combination of display advertising, paid accounts for premium features, leveraging their users to cross sell other products, data selling and things we have not even thought of yet. Social gaming providers such as Zynga that offer play money gambling have found ways to make a very nice return without making anything of the games themselves.

Think of how many users would be attracted to a gambling service that offers all the same sports betting, poker and casino products people use now but where the users break even on average and it is available to everyone in the world. There are many ways to monetise an audience of that scale."

Full write up http://bitcoin-betting-guide.com/james-cannings-blog/0-house-edge-provably-fair-and-trustless-gambling/