YouTube surpassed Wikipedia as the top social media site in the UK, and Facebook rocketed from eighteenth to third, according to the latest data from Nielsen.

Most interesting, however, was that traffic for nine of the top ten sites grew, in most cases dramatically, when Nielsen compared traffic numbers from January to those from the same month in 2007.

In keeping with my assertion recently that the UK is not, as some believe, "behind" the U.S. in the usage and importance of social media, YouTube welcomed more than 10 million UK visitors in January alone. The total population of the UK stands at somewhere north of 60 million. While it would be tempting to suggest that YouTube is reaching almost twenty percent of the UK population on a monthly basis, we know that some users are engaging social media sites from as many as three or four locations -- home, work, mobile, etc. -- so it's not a perfect comparison.

Nevertheless, we can see definitively that a tremendous percentage of people in the UK are landing on YouTube and other social networking sites, and doing so routinely.