Damian,
I work in IT...specifically which these types or web applications that utilize social media and from what I could tell, Yoovio is a very poorly designed system. The way they utilized sharing was a complete mess and large parts of the system were flash based (why it doesn't play on iPad or any iOS device for that matter) without having an html5 option. Their marketing team came up with this fancy language for the rules:
Yoov.io platform will track Entrant's online popularity using a proprietary ranking algorithm ("online popularity") on Entrant's registered Social Media Platforms that are connected to Entrant's Yoov.io account.
However, their system does nothing more then count the number of times a video is played (called from their server really) and increases a count. First off... that is not an algorithm. Second, it's a false claim to say it measures the online popularity of connected social media when it actually doesn't do anything of the sort. As we all found out, the only thing that counted was the number of times the video was played from either facebook, their site, or their wonky links from the share. Youtube plays did not count. I don't even want to get into the security issues with their platform. I deal with clients who have literally millions of facebook fans and they don't see that type of engagement on their contests. I'd be willing to bet that most of the people who were in the top 100 for points played their video over an over again. They probably have IP logs that can show it, but nobody is going to comb through 10's of thousands of lines to make sure.
As bad as Yoovi.io is, it was Guitar Center that chose to use this platform (likely a budget consideration) instead of going with something that would insure the contest would be fair. In many of these situations, it's tough to tell how bad a system really is until it's too late to reverse course but if you're putting 10 grand on the line, you'd think they'd do it right. It looks like the company that runs this is: http://revimage.com/index.php