What is the best way to rank a adult affiliate site?Social media/craiglist/keyword ?

I've been targeting keyword in google which is great, but nowadays they are making it harder to grow my following. I've only just started on the other ones like Twitter, Facebook etc. so I am still relatively new. In your opinion what way is the best one to rank? Also what do you think is going to be the best social media in years to come for adult affiliate?