In addition, e-mail was second only to customer reviews on Web sites for influencing online purchases, according to DoubleClick Performics' "Green Marketing Study," conducted by Opinion Research Corporation in February 2008. E-mail was roughly equal to search results in terms of influencing online purchases.
Bad news for e-mail marketers included the fact that consumers are increasingly willing to revoke permission that they have previously granted and that the bar for relevance remains high.
About one-third of respondents in the Merkle study also said they had stopped doing business with at least one company as a result of poor e-mail marketing practices.
In the same vein, more than half of US adult e-mail users told Merkle in 2007 that they were only willing to get marketing or promotional messages in status or transactional e-mails if the offers were relevant to them.
"There is a substantial gap between what marketers believe is relevant to the consumer, and what consumers rate as valuable," said Lori Connolly, director of research at Merkle.
"Traditionally, marketers believed that relevancy meant pushing content that is based on stated preferences or behavior, but companies need to update their view of what is relevant," Ms. Connolly said.
Consumer wariness is often justified. Some marketers are the victims of spammers, who ruin it for everyone, according to David Hallerman, senior analyst at eMarketer.
"Consumers welcome relevant, opt-in e-mails from companies they have a relationship with," said Mr. Hallerman. "But the broad spectrum of spam—any unsolicited message—continues to degrade the e-mail environment for all parties."