Base answer to your question: Yes a Facebook campaign can generate leads.
Read up on what Ryan Steward has done with Facebook and re-targeting. He just posted yesterday about this.
Depending on what your service is, you might want to advertise to a warmed up audience with re-targeting rather than just cold advertising.
Also - if you install the Facebook pixel on some specific conversion pages you can build a custom or look a like audience. Your conversion rates will be much better.
Ryan also pointed out that Facebook is very good at finding qualified buyers. The value is to build your brand and SEO and general organic social media is best to do that but to get sales Facebook can be qucik and effective if done right.