From Forbes:

Cost savings… elasticity….  scalability….  load “bursting”….  storage on demand…  These are the advertised benefits of cloud computing, and they certainly help make for a solid business case for using either third-party services or a virtualized data center.

But after the agreements are signed, systems and processes are set up, and users are retrained, something unexpected happens. The  initial use cases are realized, but then additional benefits begin to emerge — sort of like the icing on the cake, but often, these unforeseen benefits provide far more value to the business than initially planned.

Read more: http://www.forbes.com/sites/joemckendrick/2013/07/21/5-benefits-of-cloud-computing-you-arent-likely-to-see-in-a-sales-brochure/