See what others have to say about email marketing:

• “The uses for e-mail marketing are virtually limitless. Overall, e-mail marketing has proven to generate better responses while being less expensive than many traditional direct mail methods. Marketers also find the high level of personalization and the ability to track an e-mail marketing campaign at every stage to be attractive features. When you consider that recipients also prefer to receive e-mail rather than direct mail when it is permission-based, you can understand why marketers find e-mail marketing such an appealing tool.” – American Marketing Association, November 2003
• “Marketers estimate that acquiring a new customer costs five to eight times more than keeping an existing one, so limited marketing dollars should be focused on retaining existing business.” – MarketingPower.com
• “Email Marketing is the marketing phenomenon of the 21st century – the ideal way to spread the word about your products and services.” – Herschell Gordon Lewis, Effective E-Mail Marketing
• As an example from one industry :
  “Restaurants rate email marketing their most effective marketing vehicle.” – Hospitality Technology Magazine, March 2007