Marketers plan to increase e-mail use in 2008, according to a new study by online marketing services firm Datran Media.

Overall, 72% of the marketers surveyed indicated that they plan to use e-mail marketing more in 2008.

The survey, which included 1,500 marketing professionals, focused on marketers' plans to use e-mail marketing in 2008. Firms included KPMG International, InfoUSA, QInteractive and

It found that 70.5% reported plans to increase spending on e-mail acquisition and 63% to increase spending on retention campaigns.

In addition, 83% of respondents expect e-mail ROI to increase during the New Year. E-mail optimization techniques, including landing pages, subject line testing and triggered messaging, were unanimously ranked as "very important."

The survey also found that more than half of the respondents outsourced e-mail marketing.