The May visitor numbers from ComScore have been announced and show that social networking sites in the US are still growing strongly. MySpace is the undisputed number one with now more than 50 million visitors and YouTube doubled its traffic from April.

1. MySpace—51 million
2. Classmates.com sites—15 million
3. Facebook—14 million
4. YouTube—13 million
5. MSN Spaces—10 million
6. Xanga—7 million
7. Flickr—5 million
8. Yahoo 360—5 million
9. LIVEJOURNAL.COM—4 million
10. MYYEARBOOK.COM—3 million