Facebook Photos get an Ajax Upgrade. Will Pageviews Suffer?
Ajax makes Websites more efficient by bringing information to a page that previously required multiple clicks through a site. To most Web measurement firms like comScore and Nielsen/NetRatings, a site that shifts to Ajax looks like it is losing pageviews. And photos account for a lot of the pageviews on Facebook.
Coupled with the possible pageview inflation due to Beacon, traffic and pageview numbers from Facebook bear extra close scrutiny over the next few months. (The switch to Ajax in photos should start to be reflected in the December numbers). Pageviews may dip, but the metric to keep an eye on is time spent on the site (both overall and per-session). If that continues to grow, then Facebook will be doing fine.