eBay-Skype
In 2005, eBay bought Skype Technologies for $US3.3 billion, but the VoIP service company never seemed like a good fit for the online auction powerhouse. To make matters worse, eBay failed to include the rights to Skype's source code in the acquisition, which led to a costly legal battle with Skype's co-founders. By 2009 eBay was looking to dump Skype, and it eventually sold its majority stake in the company to private equity firm Silver Lake for $US1.9 billion. While eBay did make back some of the money it spent on Skype when Microsoft acquired the VoIP company for an incredible $8.5 billion last year, it didn't make up for the full amount -- or the headaches.