The report also found that larger list owners are more likely to be experienced marketers, in both b-to-b and b-to-c segments. These larger list owners look to diversify their lists using multiple growth tactics, track the sources of such growth and evaluate their list sources frequently. The tactics they use range from nonincented site registration—the most popular method—to incented site registration, to collecting e-mails in the call center.

Looking to grow your list, too? Morgan Stewart, director of research and strategy for ExactTarget, provides one secret and exposes one lie about boosting your list numbers.

Secret: Co-registration and list rental are good strategies if they are done correctly. You’ve probably signed up for a white paper or webinar and encountered it: the never-ending registration process. By the time you’re finished, you’ve been asked to sign up for 10 or more e-mail lists. This, Stewart said, is the wrong way to do co-registration. “Co-registration done well can be enormous for a marketer,” he said. “It can be done cheaply and be a way to add to your list.” When working with a co-registration partner, make sure they don’t require list signup, something that’s off-putting and will only alienate list joiners. “You never want to trap or trick someone onto your list,” Stewart said.

Meanwhile, for list rentals, you should make sure the list you’re renting comes from a reputable site that provides content that’s directly related to your product or services. You can start with trade magazines or online information sites, asking publishers how often they send out sponsored messages, what their circulation is, and what kind of click-through rates they’ve seen in the past. You’ll also want to see how engaged their readers are; check on their traffic by entering their URL into Compete.com or Alexa.com. You should also consider buying more than one list at a time and testing them against each other. “Just because a list works for one company doesn’t mean it’s going to work for you, too, which is why you have to test, and test often, to make sure it’s a good fit,” Stewart said.