I just built an app that I'm really excited about called Groupie which sends you a notification if one of your customers has a Wikipedia page, IMDB page, or large social following (Twitter, Instagram, Youtube).
Slightly creepy but very valuable. And free for up to 30 scans per month.
The reason I'm so pumped about it is because I installed it on my own store and just found out that we recently sold to a famous tech investor with 200k twitter followers which could be huge for us if we can get a mention or link or something.
Hope this can help someone :D