Now it is official:

WatchMouse research shows Facebook performance poorest of all

* Social Networking Sites Slow and Inaccessible

Popular social networking sites are frustrating users, according to WatchMouse – by making them wait. Research from the leading website monitoring company has shown that Web 2.0 sites often lag behind other commercial sites in performance – they are often slow to open or fail to load properly. WatchMouse monitored the time it took the social networking sites listed on Wikipedia (http://en.wikipedia.org/wiki/List_of_social_networking_websites), to load.

Other well-known culprits included Twitter, last.fm, Windows Live Spaces, Friendster and del.icio.us. Of the 104 sites monitored, nearly half – 51 earned a Site Performance Index (SPI) of 1000 or more, which indicates very slow load time. This was an unexpected outcome, considering most of these sites rely heavily on Ajax, which generally delivers quicker load times because the dynamics of the site do not load immediately. While first generation websites generally required a webpage to fully load each time a user clicked, the use of Ajax helps websites improve interactivity, speed, functionality and usability by instead exchanging small amounts of data with the server upon user action.

What can we learn from this ?

Performance requirements and response times < 1 second does not give you business success automatically.

Website success is today most driven by user acceptance, not by simple technological facts.

see also:

http://www.watchmouse.com/en/SPI/2008/performance_social_networking_sites.php