The administrators of these sites may not be the actual spammers but their products or services are advertised in the unsolicited commercial e-mails:

http://www.rxdiscountusa.biz
http://www.kinkfarm.com
http://www.buywus.com
http://www.straffic.biz
http://www.shopnsavecentral.com
http://ezherbal.us/jacob/vp
http://www.teflondoninc.biz
http://www.epromotionad.com