http://www.yesmail.com
2. PostMasterDirect.com
http://www.postmasterdirect.com
3. Digital Impact
http://www.digitalimpact.com
4. Focalex
http://www.focalex.com
5. ClickAction
http://www.clickaction.com
6. Penn Media
http://www.pennmedia.com
7. BulletMail
http://www.bulletmail.com
8. MessageMedia
http://www.messagemedia.com
9. Edirect
http://www.edirect.com
10. E-target.com
http://www.e-target.com