Posted on September 24, 2009 by Luke

Lost Facebook users (image Flickr CC)

Millions of Facebook users have disappeared from site’s ad targeting platform – and the company doesn’t know why.

Brands targeting the site’s long-standing student users this week have been shocked to find that only a small fraction of them are reachable.

According to Facebook’s self-service campaign scheduler, the UK currently has only 182,430 undergraduates available. There are over 2 million students in higher education in the UK.

Facebook screenshot 24 Sept 09

Individual universities show massive drops. The University of Liverpool, which had 10,690 students registered in May 2007, now has 2,300. The University of Warwick has fallen from almost 10,000 students to 2,000.

Facebook screenshot 24 Sept 09

Meanwhile in France, less than 2% of the country’s 2 million student population are apparently on Facebook.

Facebook’s UK office, set up to support local clients last year, is unsure why students have gone missing during freshers week – the busiest time in the university marketing calendar. It was unaware of any glitches in the ad platform.

In the week that Facebook COO Sheryl Sandberg has been on the road promoting its marketing solutions, this situation is another setback for advertisers who have had mixed experiences using the site.