The ads on both platforms are primarily useful for gathering a following local to the platform. For example, on Facebook, you want to buy likes/engagement with

The ads on both platforms are primarily useful for gathering a following local to the platform. For example, on Facebook, you want to buy likes/engagement with your page, not outbound stuff. On Twitter, you want to buy followers. Once you have a following, you engage with them and use the content you post to drive them to your site where you (presumably) make money from them. The ads on the social platforms are not worth anything if you're using them as general CPC ads to try to drive traffic to your site. In fact, I've found this is even true for Google/Adwords.