Until now, the IT pioneers have tended to be large enterprises with big budgets. Eventually, some crumbs from their table would fall to small and medium sized businesses. The typical SME still thinks it's pretty good if they've got Sage Line 50 and an email server that's not down most of the time.
What the likes of Google, SalesForce, and the many more niche providers of multi-tenanted software are doing is turning the current situation on its head.
SMEs start with little or nothing. Moving to web based IT services provides them with things they've never had, and could never afford to provide in house. In using such services they can often end up with something superior to that which enterprise IT teams can offer with their in house services. Small business can end up with the latest and the greatest, whilst large enterprises risk falling behind.
In terms of line of business systems, the promise of the web was never to large enterprises. It has always been a promise to smaller businesses that they will finally have access to the kind of IT that only giants could previously afford.
For big business it is quite possible that moving their stuff to a third party service provider would not even save any money. Much in the same way as large companies run their own fleet of company cars, it will probably be cheaper for them to keep running their own IT services, albeit moving them to new and more efficient infrastructure.
What should scare big business is that for the first time many smaller companies are able to get access to cutting edge IT, enabling them to punch well above their weight. Up until now David has had a pea shooter. Now that he's been given a sling and some stones, he's much better equipped to go after Goliath.