My idea is that sport fans are very good target group to propose them smth a-la "special for you".
It is easier and safer to understand and communicate (in terms of nobody else but you and the shop knows your name, e-mail and address) with what you like personally than listening to broker's "everything you want, just give us the link".
It is just my own opininon, of course...
That is an interesting sentiment the way bitcoin and sports betting seem to pair together so naturally.
Is there any existing examples?
I only bet on BeatTheStreak, which is free to bet, but has only one big prize in fiat.