Growing bitcoins can be done by using multiple methods or one good method in my opinion, I only do signature campaigns because they have a learning factor, are fun to do and also profitable without any risks plus you will grow your bitcoins.
Other than doing campaigns I do trading sometimes although I think its pretty risky so I do not do this often.
Soo you making almost the same thing as me my main income comes from signature,that is put at poloniex and making my coins grow slowly soo its always the best ,i love poloniex and their service .
I do the same, good earnings coming from signature campaign, but i don't invest on Poloniex or any other site like that, very low interest income, no?
I'm always looking for good opportunities, but the best method that i found was signature on Bitcointalk forum. Would be nice if more forums offer this earning option.