i think i no longer believe in target markets or target consumers for web 2.0 companies or sites. the thing is, if you create a service that is generally free (as most are), a lot of the considerations are no longer relevant. what does it matter if you look at the traditional selection criteria, like disposable income? you’re not going to ask them for money anyway. also, you can’t predict what users or communities are going to use your product. and you often don’t build those communities. it’s probably easier and better to focus on providing a solution to a problem. people who have that problem and like your solution will use your service, and they will probably bring people with them.