http://www.costargroup.com
2. Reis
http://www.reis.com
3. RENTV
http://www.rentv.com
4. NREIonline.com
http://www.nreionline.com
5. GlobeSt.
http://www.globest.com
6. PikeNet
http://www.pikenet.com
7. Black's Guide
http://www.blacksguide.com
8. REITNet Online
http://www.reitnet.com
9. NAI Direct
http://www.naidirect.com
10. NARIOT Online
http://www.changingrealestate.com