I'm using Bitcoin with my Steam and Xbox accounts, most of the time. It's hard to use it in a daily routine especially when there's no shop nearby accepting BTC as a currency. Also, on gambling websites if they count too.
Most of the users are spending their coins in gambling hoping to multiply it quick, but the important thing is that it allows the circulation of bitcoin in the system which is really important for the higher price of bitcoin in future.
Gambling alone will not be important, as the gamblers are lesser in number and with that newbies will consider it as the currency of gamblers, there are a lot of online stores which accept bitcoin we should have to go there also.
Yeah its better to spend bitcoins on productive things instead of wasting it on gambling, as gambling never promises us regular returns so its better not to put our bitcoins into it.