Two things are worth highlighting in your comment. One is that the examples are "yesterdays" companyies that are not all that new (in dog years;). Two, is that the entry point and the profit sweet spot were not the same. The Bet now (as per the article) is that markets that before were not likely adressable directly, are now so. Ie, there is a change in the enterprise maket (ie, latent demand) that is now directly accessable as a go-to-market strategy.
Agree. However I'd say that for technology (software and maybe now hardware), consumer to enterprise is the new normal. Meteor for example is going this approach. Individual developers are not exactly consumers, but before a platform is ready for production most users are tinkerers, which in my mind is a consumer that is part of the maker movement. Eventually those maker consumers help take something to maturity where it eventually gets adopted by the enterprise. With the Arduino, Raspberry Pi and Beaglebone, I think we're going to see consumer hardware startups mature and at least one will be a huge hit because it's a consumer tech hardware company that ends up having enterprise tech hardware relevance.
I'd say that the biggest change in the enterprise space is that individuals are increasingly responsible for purchases as opposed to some centralized purchasing department. Grassroots IT is the only adoption strategy with an element of virality.