Nice work, just make sure you reinvest the money rather than just waste it and you will be earning $1000 in no time.
If $300 is enough for you / month, that is very sad. You have good traffic. Buy Guaranteed Adsense account, do something special / unsupported and earn 10 times more. With Guaranteed Adsense you can click for itself, hide, manipulate ads ... you never will be banned.
@n.mojenka What exactly is a Guaranteed Adsense account? I've never heard of it. How do you go abot obtaining one? Thanks in advance. Also for the original poster, are you still doing well and what is your Youtube strategy, if you don't mind sharing?