Rohit Bhargava of the Influential Marketing Blogs has these great stats about Twitter on his blog:
Last month a social media analytics provider named Sysomos released a comprehensive report on Twitter usage. The problem with most analysis on Twitter, though, is that it is limited by the minimal amount of data that Twitter collects. So, to fill the gaps, most reports do things like guessing gender based on real names or pulling data from keywords in people’s biographic information. This often yields some questionable results – and the Sysomos report is not immune to this (for example, they find that 65% of Twitter users are under the age of 25, but base this on only the 0.7% of users who actually disclose their age).
Looking past these small points, the report does share some fairly interesting observations and stats as well if you dig a bit deeper. Here’s my read on the 10 standout conclusions that the report offers to help you (and your brand) better understand the potential uses of Twitter: