Can you really offer something better or different than all those sportsbook sites out there? Competition is pretty fierce.
The obvious answer is that if you offer better odds than everybody else, people will do business with you.
Yes OP, I don't think you are already aware on how many they are out there. Just go to the gambling section and browse a bit. This will not be an easy task if you did code on doing it.
Keep in mind that you will have to earn your reputation and this will take quite some time since people are essentially sending you their bitcoins. This has to be done done seriously, honestly and with many promotions as some have already suggested or don't get into this.
