Facebook has become a potent force for reaching audiences but not yet a source of ad revenues …read more

From:: http://www.ft.com/cms/s/0/6c23f006-beca-11e4-8d9e-00144feab7de.html?ftcamp=published_links%2Frss%2Fcompanies_us%2Ffeed%2F%2Fproduct