Re: 3000-3500 bln is a bit more than 20-30 bln
> 1% of the IT spend = cloud, sort off.
Except: cloud isn't all *that* cheap for traditional server applications which run 24x7.
In Amazon, an m4.large virtual machine (2 cpu / 8GB) will cost you $55.19 per month on a 1-year contract, which is over £500 per year, plus EBS storage charge, plus Internet traffic charge.
Buying a basic Dell R230 or similar is around £700 when an E-value code is available. Furthermore, you can cheaply upgrade it to 16GB or 32GB, whilst similarly enlarging the VM will cost you 2x or 4x as much.
The management is pretty much the same: in both cases you're responsible for managing both the OS and the applications on top.
Of course, the Dell needs to be powered, and it needs rack space.
But what you are really paying for with EC2 is the flexibility to turn service on and off on-demand - plus the fact that if a box dies, your workload will be immediately restarted on another box. And in the case of Windows workloads you're paying your Windows licence per hour, rather than having to buy it all up front.
Those advantages evaporate when you have a sufficiently large pool of servers yourself.