However, compared with the same period last year, MySpace seems to be maintaining its strong growth in audience. According to Nielsen, the site’s unique user count for September represents a 24 percent increase versus the same month last year.

Similarly, while all reports point to Facebook with its meteoric growth – its audience in September increased by a whopping 133 percent versus the same month in 2006. However, its unique user slipped from 19.2 million in August to 18.1 million in September, a decline of six percent.

Most social networking sites experienced exponential growth from year to year as of September, but sites like Classmates.com (minus two million users) and the kid-targeted Club Penguin (minus 200,000 users) also recorded audience declines versus August, Media Week reported.