“You have to fall somewhere in the middle of one-to-one marketing and e-mail blasts to everyone,” Webster said. “Marketers have a million priorities, so they need creative strategies that will drive the results they need without spending too much time on it.”

Webster offers the following tips to engage different groups of customers on your e-mail list so they ultimately make that purchase:

1) Use Web analytics to track behavior. E-mail subscribers often give inaccurate survey responses, and prospect-reported data gets old fast, Webster said. Instead, track prospects’ “body language” by watching what they do with their e-mails and on your Web site. Using tools such as RFM (recency, frequency and monetary value) analysis will help you find that 10% on your list that’s highly engaged.

“You’re letting the e-mail behavior of your subscribers directly communicate to your salespeople who needs a call today,” he said.

2) Replace e-mail blasts with life-cycle messaging. Avoid sending the same e-mail blast to everyone; the churn rate of finding new subscribers will cost you more than identifying the most interested people on your list.

Instead, craft more-targeted messages to subscribers by knowing what stage of the sales cycle they’re in. To gain those data, you need tools that count the “clickers” and the “openers,” Webster said.

“Today’s disinterested prospects are tomorrow’s customers, so you have to talk to them the right way to move them on in the cycle,” he said.

3) Personalize for higher engagement. When you show your prospect you’re listening to their needs, their level of engagement typically rises, Webster said. Personalize the content of the e-mail based on prospects’ level of interest, such as information on specific products, vertical industry or where they’re located, Webster said.

“If you’ve got someone who’s raised their hand, convert them to a sale by giving them a name of someone on the sales team to call or a link to their e-mail,” he said.