Well, as for me, I post my ad in twitter, facebook, and the rest of other social media sites. So far I have more than 12K+ Twitter followers and more than 100+ facebook groups with total of around 200K members. Yesterday, I heard about tribepro.com which is a very effective way to drive traffic to your site. I haven’t tried it yet but I think its also effective way to promote the gig or affiliate link.
I also use Social Media sites, But I mostly try to do it with my blog.