In October 2005, eBay Inc. acquired Skype Technologies,[88] developer of the Skype VoIP and Instant messaging service, significantly expanding its customer base to more than 480 million registered users worldwide. eBay later sold a majority stake in Skype in November 2009, while retaining a minority investment.[89] This eventually led to the sale of the entire Skype business to Microsoft for $8.5 billion in May 2011.[90]