This is otherwise known as the endless version number system. I remember starting to use Microsoft 2.0, before that it was WordPerfect 5.1, or worse Multimate 1.0. This is why the "2.0" brand that is associated and attached to web-based technologies and services is so laughable. Soon, someone will be saying they are a 3.0 company, and so on. This is herd mentality. Go with the flow. Run with the pack.
This is a concept developed by technologists for the business and not-so-savvy-about-tech community. It gives a quantitative number to such virtual products like social networking, blogs, wiki, SEO, CPC, tagged "indexes", etc. These all add value to some business models, but not in the proportions being inflated by today's online media outlets. This doesn't embrace innovation, IMHO.
True innovators would kick the "2.0" part of their sales pitch to the curb, announce that they've found a real number between 6 and 7, and market that to the masses.
