Probably signature campaigns for the established members of this forum, The prices they offer in the services section are pretty good and reach 0,20-0,30 for high ranking members, the rate is lower in proportion to the lower status.
Signature campaigns got a good price for their advertisements but this wont be enough if you are looking for more bitcoins. Perhaps having some other options will also be good. Signatures will be your side earning.
To fulfill their bitcoin users typically use the signature campaign account of more than one order for its profits doubled. But also there are trying to gamble in order to get a lot of bitcoin. It's up to you want to use any way. But I really like using sebih of the signature campaign account because I think the benefits are numerous.