Most house edges for Bitcoin casino's are ~1.5%. For a lot of people, in order to obtain BTC, you can look at commissions and such totaling well over this. If looking at things in regard to expected return or your expected value, gambling in order to obtain bitcoins would be more feasible in the long run. Sure, there's no variance involved in buying off an exchange, but for those looking for a risk, gambling could be a nice alternative. Gambling is frowned down upon due to the fact that you can never win, but in fact you can when viewing it this way. I understand that expected value in regard to gambling is additive (No, not addicting, additive), so in order to achieve this higher expected value, the less you bet the better.
Obviously some people can be smarter or more efficient when buying their BTC in order to avoid commissions and other means such as the sometimes large ranges between the bid and ask. For them, this doesn't apply. But for people like me, who are looking at large commissions when purchasing BTC (Due to personal conditions), and enjoy a risk, this is a cool way to look at things.
By all means, i don't recommend doing this. It's rly just variance vs EV, and your paying more for a lower (Well 0) variance.
Feel free to point out any flaws in my logic by the way.
If I'm not making much sense & your interested, have a read of the wiki pages.
Variance:
http://en.wikipedia.org/wiki/VarianceExpected Value:
http://en.wikipedia.org/wiki/Expected_value