Data on Twitter Decline Stacks Up - eMarketer
According to data provided to eMarketer by Nielsen, traffic to Twitter.com was down a dramatic 27.8% between September and October 2009, falling to 18.9 million unique visitors. Nielsen is the latest in a list of research firms reporting declines at Twitter.com. comScore said unique visitors were down 8.1% in October, while Compete reported a 2.1% decline.
It has not been unusual to see wide shifts in Twitter traffic readings among Web measurement firms, and different methodologies likely account for the varying visitor counts. But one thing is clear: traffic to the Twitter.com Website is declining month over month after a period of huge gains.
The decrease in visitors could mean either falling interest in Twitter or simply migration to other platforms, such as third-party applications and mobile access.

The median age for Twitter is now 31, while MySpace is down 26 from its previous 27 in May of 2008; and Facebook has risen significantly from 27 in May 2008 to 33 now.
