Facebook has made several improvements to ad targeting in its self-serve tool, including the ability for US advertisers to target specific zip codes through the self-serve tool, Ads Power Editor, and Ads API. Previously, advertisers could only geo-target ads to cities, states/provinces, and countries. This will be beneficial for small and local businesses who can now target potential customers within walking distance. The option could attract the long tail of small businesses to Facebook Ads, driving revenue growth.
Sure there has been success with advertising through facebook. Facebook is huge and is probably the easiest way for anyone to reach big crowds of potential customers that 'trust you' because you have five mutual friends lol.