In 2007, the most viewed YouTube videos were mostly user-generated content. In 2008, the Top 10 list saw a lot of music videos with high production value making the list. In this recap for 2009, you’ll see that user-generated content still has merit when it comes to producing a video with the potential to go viral. To quote Hubspot, the authors of the book Inbound Marketing, the key to going viral is to produce “remarkable” content and because the social media world is all about authenticity, it’s always good to show transparency whenever possible.

For the full list of the top 9 videos of 2009 and one writer’s thoughts on the keys to viral video success, check out this blog post by Reel SEO.