With the signature campaigns this is already possible and you can do some trading or gambling without any doubts for that.
I recommend to do some signature campaigns because its way more safe than other methods nowadays.
To earn 0.1 btc only from signature campaign you need to have multiple account enrolled in multiple campaigns and then that amount can be earned easily on weekly basis.
That is the hard thing to do if you are using a lots of account for signature campaign for me it is hard.. you can not post and make fast reply here for me it takes a long typing before i can make a one post.. unless if you are joining in high paying signiture campaign but i think its still not its hard.. maybe for india people they can do this because more india people are always fast in typing.
Having multiple accounts would be possible but its not tolerable here on this forum and its illegal especially when you are joining signature campaigns because its already considered as farming. you could actually easily to achieve 0.1 per week on signature campaigns but it depends on you if you could handle it.