Google’s YouTube leads all video sites in unique users, stickiness, and growth over the past year. Combining YouTube with Google Video, Google dominates the top video sharing sites, with over 4.4 times the users as its nearest competitor. Despite accounting for a small fraction of the files on the Internet, web videos from YouTube alone account for more than 10% of the traffic. That is why video optimization is important for web site performance and saving bandwidth. Broadband penetration among active Internet users grew to 83.23% in US homes in June, up 1.05 percentage points from 82.18% in May 2007.