This Facebook offer ad makes it obvious what customers would be signing up for when they click the "Sign Up" CTA button below the picture. Offer ads can easily mislead viewers into pressing their CTA just to get them to click on it, but it ultimately doesn't convert viewers into customers. BSC's approach above is clear and upfront about what it's offering throughout its conversion path. Does Facebook pixel only track traffic from Facebook?
You also have the option to select a Custom Audience -- this allows you to target people on Facebook who are in your company's contact database, visited a page on your website that has a tracking pixel, or use your app or game. To learn more about how to set up a Custom Audience on Facebook, check out these instructions. (And for more on the specifics of these criteria, visit this Facebook targeting resource.) How to prepare and market using Facebook Ads