• 49% of email marketers said their newsletter routinely justified themselves. - MarketingSherpa “Email Marketing Benchmark Guide 2008″ (2008)
• only 10% of email marketers said their newsletters were not being justified by revenue. - MarketingSherpa “Email Marketing Benchmark Guide 2008″ (2008)
• Consumers who subscribed to email newsletters generated 34.25% more product sales. - ConAgra Foods case study in association with MarketingSherpa (2007)
• 83% of survey respondents use email marketing to create and distribute newsletters - an increase of 23 percent over last year. - Constant Contact, Inc, The 2007 U.S. Small Business Summer Outlook (2007)
• 40% of small businesses execs want to see “how-to” type of content in their (email) newsletter. - Bredin Business Information (2007)
• 26% of small businesses execs want to see topics about strategy and leadership in their (email) newsletter. - Bredin Business Information (2007)
• 30% of small businesses execs say they had an improved image of a vendor from the (email) newsletter they received. - Bredin Business Information (2007)
• 64% of small businesses execs said they decide whether or not to open the (email) newsletter based on who it’s from. - Bredin Business Information (2007)
• 45% of small businesses execs want to receive the (email) newsletter weekly, 34% said monthly. - Bredin Business Information (2007)
• 50% of the largest online retailers offer one-click sign up for their email newsletters. - Email Experience Council/RetailEmail.Blogspot (July 2006)
• 27% of the largest retailers offer subscribers some kind of incentive to subscribe or a reward for subscribing to their email newsletters. - Email Experience Council/RetailEmail.Blogspot (July 2006)
• 70% of the top retail sites in Google’s paid search listings offered email newsletters. - JupiterResearch (March 2006)
• Average time allocated to a newsletter after opening it only 51 seconds. - Jakob Nielsen (2006)
• Of the largest online retailers that send welcome emails, 34% of them offer a discount, reward or incentive to encourage them to make a purchase with the retailer. - Email Experience Council/RetailEmail.Blogspot (Sept 2006)
• News feeds are definitely not for everybody and they are not a replacement for email newsletters. - Jakob Nielsen (2006)
• The majority of email marketers are failing to use email as a relevant marketing tool. His research found relevant messages can lead to almost as many sales as free or discounted shipping offers. - Jupiter Research VP and research director David Daniels (2006)
• 44% of marketers surveyed believe the biggest challenge in email is providing relevant content. - eMarketer (2006)
• Newsletter-style layout for promotional emails generated average click rates of 7.1 percent, compared to average click rates of 6.2 percent for single-image “postcard-style” messages. - Silverpop (2006)

These Email Newsletter statistics have been compiled by www.emailstatcenter.com. You can find hundreds of different email statistics on their website, however the above is my own compilation of relevant and interesting statistics that relate to Email Newsletters.