RADIO

http://www.arbitron.com - Leading radio ratings service.

http://www.radioandrecords.com/RRRatings/ - Search Arbitron ratings by market.

http://www.fmqb.com/ratings.asp - Search Arbitron ratings by market.

PRINT

http://abcas3.accessabc.com/ecirc/index.html - ABC circulation information.

http://www.bpaww.com/ - BPA circulation information.

INTERNET

http://www.alexa.com/site/ds/top_sites - Internet traffic rankings.

http://www.hitwise.com/ - Hitwise provides insights on how 10 million US Internet users interact with more than 1 million websites, across 165+ industries.

http://www.nielsen-online.com/ - a global leader in Internet media and market research.

http://www.comscore.com/ - Measuring the Digital World.

http://www.quantcast.com/ - Quantcast is a new media measurement service that enables advertisers to view audience reports for millions of sites and services to build their brands with confidence. The free service empowers publishers to demonstrate the unique value of their audiences by tagging their websites, videos, widgets and games for direct measurement.

TV

http://www.nielsenmedia.com/nc/portal/site/Public/ - Leading TV ratings service.

DIRECT MAIL

http://www.usps.com/directmail/welcome.htm - USPS direct mail information.

OUT OF HOME

http://www.oaaa.org/ - Outdoor Advertising Association of America.

http://www.ovab.org/ - Out of Home Video Advertising Bureau.