http://www.coindesk.com/bitcoins-gambling-boom-just-getting-started/Some Bitcoin gambling platforms do $10 million+ a month in Bitcoin volume, so I'm guessing you're looking at $100 million a month Bitcoin gambling volume.
Considering BTS is about 1% the size and daily volume of Bitcoin,
we could be talking up to a $1 million in monthly BitAsset volume right now if BTS users were given access to BitAsset gambling.Edit: An internal option that only let you wage with BitAssets (but not BTS) would be ideal. It would get us using the wallet & BitAssets more and massively increase BitAsset volume.
Even an external site would be fantastic though and from cursory research would do big volumes from inception. (No advertising required for the first mover either & BTS users would use it in a similar ratio to what Bitcoin users do.)