I don't recommend it, but some gambling sites (nitrogensports.eu, cloudbet.com, directbet.eu, sportsbet.io, and some others) don't make you pay a fee when you withdraw, so you could use them. Directbet might not be a bad choice as they kinda advertise it as a service, but I don't think the other sites would be happy if you did it. You might risk getting banned from the sites, or asked to pay the fees that you spent.
Interesting, withdrawal is free but you still you have to pay transaction fee to sent bitcoin so it is only half good.
So if you just want to send bitcoin to someone it will be easier to to just send BTC directly without another service meddling in.
No, most of the bitcoin services (gambling sites, exchanges and web-wallets) are not having the practice of charging withdrawal fees but they will ask us to pay transactions fees or deducting only one fee, it can be for both, example: poloniex.
I am already into using directbet which is very similar to xapo, no fee I need to pay while withdrawing. So, it is not half good, it serves the exact purpose of using a wallet services with zero sending fee.