Google Adwords PPC program where webmasters can create their own ads and choose keywords.
http://adwords.google.com

Yahoo! Search Marketing  Put your business in front of potential customers at the precise moment they're searching for what you sell. http://searchmarketing.yahoo.com

CPX INTERACTIVE CPX Interactive is an online ad network, dedicated to both advertiser and publisher return on investment (ROI).. www.cpxinteractive.com/  

Casale Media  Internet market statistics, news and reports. Focus on comparing its market data results with those published by other well-known consulting groups. www.casalemedia.com/

Commission Junction Global leader in Affiliate Marketing, Online Marketing, and Search Engine Marketing. www.cj.com

Tribal Fusion Site Representation Company focused on high quality sites with targeted content and significant reach. www.tribalfusion.com

ClickZ Expert advice about Internet marketing, email, brand and interactive marketing, and search engine marketing. Read the latest Internet advertising news, e-commerce market research, Int  www.clickz.com

Marketing Terms  Marketing and internet marketing terms, acronyms, course syllabi, and recommended links www.marketingterms.com 

Internet Marketing Center  Tips and strategies for promoting a business online. www.marketingtips.com  

BtoBOnline Online magazine for marketing strategists. Provides current news and techniques for web marketers. www.btobonline.com

InternetNews provides real-time news updated throughout the business day, covering IT issues and Internet-related technologies  www.internetnews.com

KnowThis  A virtual library containing information, resources, and reference for professionals, academics and students in traditional and internet marketing, and advertising. www.knowthis.com