In 2007, nearly six in 10 companies will send their e-mail recipients to pre-populated Web forms if they want to opt-out, up from 30% who did so in 2005. Nearly two-thirds of e-mail opt-out links in 2007 led to a page for registrants to make changes to their subscriptions. In 2005, only 12% of e-mail marketers did so.

"Even though including easy-to-find forms for e-mail list opt-ins tends to increase the response rate, opt-in requests gain greater effectiveness when they're part of a larger process," said David Hallerman, senior analyst at eMarketer.

"That could mean asking the customer to sign up for an e-mail list when they make a purchase, request further information or some other kind of engagement," he said.

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