According to an IDC report, the on-demand application services market is projected to grow from $665 million in 2003 to $3.6 billion by 2008. The growth has made even traditional companies, such as SAP (nyse: SAP - news - people ), enter the game.

Basically, an on-demand platform is a single version that all customers use. Thus, there is no software obsolescence, support of legacy versions and support for multiple operating systems. (Forbes)