DoubleClick Ad Planner

DoubleClick Ad Planner by Google is a free media planning tool for publishers to focus market there target audiences. I found really cool was the 1000 most-visited sites on the web check it out here stating that Facebook is number one at the moment and updates every month.

Which websites attract your target customers? 

Refine your online advertising with DoubleClick Ad Planner, a free media planning tool that can help you: 

Identify websites your target customers are likely to visit

• Define audiences by demographics and interests.
• Search for websites relevant to your target audience.
• Access unique users, page views, and other data for millions of websites from over 40 countries. 

Easily build media plans for yourself or your clients 

• Create lists of websites where you'd like to advertise.

• Generate aggregated website statistics for your media plan.

DoubleClick Ad Planner can be followed here for those of you that want to learn more or just want to check it out.  I would strongly suggest you check out the 1000 most visited sites list, at least the first page, it's quite interesting.