It's more about forecasts and assurances. If you're financing the network that is currently doing X traffic, but expect it to grow by quite a bit soon, you're going to ask "is this solution going to cover everything?"

The Cisco guy is going to sure 'Sure! We can cover everything!'

The OSS off the shelf guy is going to ask 'Well that depends on the growth.'

At that point, most of the businesses just throw some money at Cisco so they don't have to worry about anything.