Email was the No.1 tactic that marketers targeted for increases in the run-up to the 2009 holiday season, followed by SEM & SEO, online banners and coupons. Also, according to MarketingSherpa, emails to house lists or rented lists generates approximately 10 to 20%  of website visitors to eCommerce sites.
“Email marketing remains the underfunded, underappreciated bulwark of online marketing.  Although it routinely gets good reviews from all types of online marketers, email is less likely than other tactics to get its own line in the budget, or to be routinely upgraded …

“Email Marketing Metrics Report” – 2009 from MailerMailer represents a must-read publication for people interested in email marketing.  The 38-page report is filled with charts, tips and data that provides businesses with relevant information to help them adjust their email marketing strategy to cater to their audience’s changing needs. Here are the main findings for this report:

Email marketing open rates by industry and list size