I went to a killer Adwords class last week - and one of the sections was on a new Adwords tool called AdPlanner. It has all sorts of demographics data on major websites.
Since I know a lot of us advertise on PsychologyToday.com - I thought I'd let you see what Google has to say about their visitors. Please note this is Google's data - not mine - and is all based on U.S. data.
They estimate 240,000 unique visitors a month come to PT, and accumulate 1.3 million page views.
And I've pasted the other info below - enjoy! Best, Peter