According to comparison figures from August 2007 released today by Nielsen//NetRatings, US teenagers aged 12 to 17 who visit both MySpace and Facebook spend more time at each site than those who visit just one site or the other. During that month, teens who visited both sites spent on average 20% more time on MySpace (than visitors to MySpace alone), and on average 26% longer at Facebook (than exclusive Facebook visitors).

From the graph above, it appears that US teens are spending at least four times longer on MySpace than on Facebook. According to Jason Lee, media analyst, Nielsen//NetRatings:

Teens who enjoy social media are intensive users and highly engaged. They are venturing onto multiple networks to experience new features and broaden their connections. This demographic is typically drawn to what’s new, and since they are growing up online, they are not afraid of learning the latest Web technologies. MySpace introduced a lot of people, especially young people, to social networking, and that forum continues to be overwhelmingly popular. But Facebook’s innovative features, many born out of partnerships with third party developers, are driving user growth. Teens continue to interact with friends on MySpace, but have not hesitated to follow their peers to the latest social networking brand. At this point, each site has a unique offering, and teens are happily visiting both.

Here are a few more interesting statistics from this survey:

• Facebook’s total unique visitors grew by 117% from August 2006 to August 2007 (from 8.9 to 19.2 million visitors).
• Facebook’s number of visitors aged between 12 and 17 grew by 122% during the same timeframe.
• 80% of Facebook’s visitors in August 2007 also visited MySpace.