Stamford, Conn.--Marketers sending permission e-mail to their customers are finding that their messages are achieving response rates exceeding Web advertising, direct mail and "spam," according to a study released Monday by IMT Strategies, a sales and marketing research firm. According to IMT Strategies' research, more than half of all e-mail users feel positively about permission e-mail marketing, and nearly three quarters of users respond to permission e-mail with some frequency. By contrast, the findings show that "spam" can hurt the brand image of companies that use it: 64% of customers had "very negative" reactions to receiving spam. The study also found that 80% of e-mail users have granted marketers permission to send them occasional e-mail promotions; almost half of e-mail users with greater than two years' experience say they get "too much" e-mail; and the majority of marketers (70% of the 169 campaigns reviewed) do not measure the performance of their e-mail marketing campaigns, despite the wide availability of measurement tools. The study methodology included a random phone survey of 403 adult U.S. e-mail users and phone and Web surveys of more than 200 leading e-marketers.