You can use signatures campaign,faucets,news bonus from gambling sites.
Check games and round for new giveaway.
Sell services on marketplaces.
Resolve captcha for bitcoins.
Solve captcha bitcoin whether it is tantamount to cramps?
And what is meant gambling bonus? I was unfamiliar with it
Gambling bonuses were either a sign up bonus or deposit bonus or no-deposit bonus. Its a nice way to get free bitcoins but there are certain requirements to meet so you can be able to withdraw the bonus to your own wallet. Its not easy though to meet a wagering requirement but when you successfully able to, its worth it
At some places you need to wager x25 times and at some, x50, so do you really think that this is possible???
Also, if you lose your own deposit before wagering, you will get your bonus swiped off instantly, so what's the benefit???
Also, gambling is risky, and chances are, you might lose more than you win if you don't know what you are doing...
Of course its really possible. I know some people who already reached it and even me, I've successfuly withdrawn a not so big amount(but worth it) from a promotion bonus after meeting the casinos wagering requirement (50x). I'm so lucky that time. Its possible but you need some luck. Also, I never tried deposit bonuses.