Direct Response Marketing:

"List of businesses, organizations, and associations providing information, services, and resources for direct marketers."

Brand Republic:
"Leading source of news and information for marketers."
Sister magazines include Marketing, Revolution,  Campaign, and PRWeek.

DMA Consumer Assistance:
"The DMA Consumer Assistance website provides information and tips about shopping and consumer rights."

The DMNews:
"The online newspaper of record for Direct Marketers."

eMarketer:
"The online source for Internet and E-business research and analysis."

The eMarketing Association:
"International association of individual marketers, companies, and governments."
Provides resources, certifications, educational programs and events to it's members and the marketing community."

Guerilla Marketing:
"Jay Conrad Levinson. The father of Guerilla Marketing."

Inside Direct Mail:
"The newsletter that brings you monthly access to the secret world of direct mail."

Promotional Marketing:
"The source of product information for distributors."

The Direct Marketing Association:
"Helping direct and interactive marketers succeed."

The Direct Selling Association:
"The national trade association of the leading firms that manufacture and distribute goods and services sold directly to consumers."

National Mail Order Association:
"The 'HUB' of direct response marketing for small to midsize firms."
Provides critical business resources for companies involved in direct marketing.

Marketing Research Association:
"Your link to a world of powerful resources."

Business Marketing Association:
"Education, training and professional development in business-to-business marketing."

The Institute Of Direct Marketing:
"Provides membership, training, qualifications and information services to keep marketing professionals abreast of new technologies."

Think Direct Marketing:
"Direct Marketing products and services."

Who's Mailing What! Archive:
"Direct Mail competitive intelligence."

Nielsen Media Research:
"Nielsen Media Research defines the global standard in online audience measurement. You can rely on the syndicated, customized media and market research to stay informed about your competition, understand your audience and engage your customer. Each service-tailored to a particular research need-features online data delivery 24x7; timely, written analytical reports; and one-on-one consultations with our industry analysts.."

GreenBook: Find Market Research Companies and Focus Group Facilities:
"The GreenBook is a worldwide directory of market research companies and focus group facilities. The most reliable guide for buyers of market research services looking for suitable suppliers."