I have documented myself about these sites, there is no existing site that is perfect for players. What do you think ? how should it be, design, games, contests?
That means you want bring something new for players? If there is no existing site that perfect for player, so how want make it perfect? Actually what I guess, gamblers always try to found that a gambling site should have everything what they need. If everything is there according to them then it's perfect for you. So most likely you should have everything gambling related on your site.
Share more details about your concept then we could leave our opinion. Likely you should move your thread on Gambling Discussion board from lower left.