Do you think that gaming sites provide the opportunity to earn bitcoin? I wonder whether you have the experience of playing games of chance, and how many have you managed to earn this way. If you honestly, I do not trust gambling, and I am sure that there may be more to lose than to earn.
Yes. It could be 'double profit'. While you are playing games, you're also can earn bitcoin at the same time.
I'm not gamers anyway, but as far i know there is a games that you can earn altcoin (digibyte), don't know about bitcoin.
Gambling is not a recommendable source of getting bitcoin nowadays. If you really want to get bitcoin, then you should try either trading or by selling your services or the combination of these two. Trading is most especially rewarding in both short and long term run.