bLikify
(A picture by Shikariwilly that sums up what this plugin is about)
Summary
Now, all of us know of the popular plugin votifier, but most of us also realize the small sphere of influence that most voting websites have. People might see your post on the minecraft server list if they look, but odds are that the casual gamer who just wants a few friends to play with won't even look at the website. This is where bLikify shines. Basically, bLikify offers a way to reward players (run commands) when they like your facebook page. This brings the same form of advertisement, but on a much more popular platform.
@ceoepts
It can't be done. Here's the example, Say me and you both do /like. We both go to facebook I know you're going to like it though, so I don't press like and just wait. Who does the plugin give the reward to?
Sadly, issues like this prevent multiple people from using it at once. :(
FIRST!
But any idea of having the players in a hashmap? So multiple people can like at once.