Youtube Music Awards Question
 

This is probably a dumb question but I don't really get social networking.

Anyway,

Youtube say that you can search YTMA on Youtube and you will be provided a list of nominees. Share a video by fb, twitter or G+ and it counts as a vote. If one of your friends then likes or shares that video it counts as another vote.. and so on and so forth.

My question is, how does YT keep track of these votes?

"press like and subscribe"