I already linked you dozen of times about that... it is from MS.
http://www.gamespot.com/articles/28-million-xbox-360s-sold-17-million-on-xbox-live/1100-6202733/
http://www.eurogamer.net/articles/xbox-360-sales-hit-28-million-worldwide
http://www.gamesindustry.biz/articles/360-hardware-sales-top-28-million
http://venturebeat.com/2009/01/05/microsoft-says-xbox-360-sales-top-28-million-to-date/
http://kotaku.com/5124107/microsoft-weve-sold-28-million-xbox-360s
They even said they sold way more than expected on holidays.
According to these articles, at the same point in time PS3+ 360 had sold 48m.
....
PS4 is at about 54m. Alone.
Nuts.