It was just in 2005.  Others may have thought about it earlier than this.  Yet, this article which appeared at the MIT Sloan Management Review certainly opened the horizon for that 'big switch'.

He sure was on to something but did he foresee the hype? By his very opening lines, Nick Carr wrote about a transformation that would seem unthinkable just like what happened in the early 20th century.

 

After pouring millions of dollars into in-house data centers, companies may soon find that it's time to start shutting them down. IT is shifting from being an asset companies own to a service they purchase.

 

Very interesting read!