The only thing that could entice me to use a totally new service was if it was provably operated and ran by an entity/organization/individual which already had a significant history and good reputation from running another service, and which I had personally used. If ChipMixer, for example, opened a betting site (and I could be 100% sure it was ran by the same people and that they hadn't been compromised), then I'd have no qualms with giving it a spin. If you are a brand new service/organization, then I agree with most of the posts above. I'm not sending you a single satoshi until you have a solid history, reputation, and community reviews. I'm also not sending personal identifying information to any third party service, so if you require that, I'm immediately out.

Given how many new exchanges/casinos/gambling sites/mixers/web wallets/whatever we are bombarded with pretty much every day, and that the vast majority of them turn out to be complete scams, it is difficult to entice users to try out any new service. In terms of your casino example, many casinos offer a faucet so users can sign up and play for free. Once some users have verified they can withdraw from faucet winnings, they may be enticed to deposit and play with their own money. From there, reviews and reputation can slowly be built up.