Firstly, very good work in defining customer segmentation from Claritus, which can be very useful when planning/thinking /designing your web app idea, especially in this web 2.0 era.
Secondly, when it comes to scope of web 2.0 apps today, the word is still "informainment". Is that it? How do you take this movement to the next level?
On Blogging, Dave Sifry says
Technorati is tracking 70 million blogs now, at a rate of 120,000 new blogs per day - 1.5 million new posts per day. He compares to "an enormous amoeba". He says there are 15.3 million "active" blogs (21%). He also notes the mainstreaming of these technologies - and that people may not even notice they're reading a blog. 12% of the top 100 sites 6 months ago were blogs; but now he says it is 22%. Mainstream media is still at the top (NY Times etc), but there is growth in the blogs.
He looks now at the behaviors of the top bloggers. He says these are effects, not necessarily causes. He notes that influential bloggers post more frequently, on average twice a day. Whereas "magic middle" bloggers (about 3M) post on average once a day. Also influential bloggers have been at this at least 1-2 years. Finally, 88% of the top 100 is different than one year ago - i.e. it's very fluid.
In language, Japanese is now the top language - 37%. However there are undercounts: French, Korean and Chinese. English is now 33%, only one third.
Tagging has become a mainstream acitivity in blogging, according to Sifry - 230 Million tags over two years, with 37% of blog posts using author tags.