Marketers know that the ability to harness customer data across platforms enables them to create more meaningful messaging. But the enormity of the task leaves many at a loss of where to begin.

Lack of resources and the difficulty of integrating e-mail and Web analytics applications are most often cited as the reason marketers don't use Web site clickstream data to target campaigns. But a wave of newly formed partnerships between e-mail service providers and Web site measurement firms means there's never been a better time than now to begin. In addition, marketers who lag behind risk being left behind. JupiterResearch has reported that 41 percent of e-mail marketers say they're planning to begin using Web site behavioral clickstream data as an e-mail targeting tactic.

The benefits of using Web site behavior to power e-mail marketing campaigns can be substantial. In fact, a May 2005 study by JupiterResearch found that, on average, targeted e-mails that leverage Web site clickstream data generate nine times the improvement in revenue; and they generate 32 times more in net profit over undifferentiated broadcast campaigns.

So how to begin incorporating Web analytics into your e-mail campaigns? I suggest you take it one simple step at a time. Consider approaching your e-mail/Web analytics integration by reviewing "The Five Ws" (Who, What, When, Where and Why) to gain a more complete understanding of customer behavior. Using Web analytics data to answer these questions about your e-mail customers can help you better understand their needs and more effectively market to them.

1. Who hasn't completed a transaction? When an e-mail customer visits your site and places an item in a shopping cart but fails to complete the process, you have an opportunity to reach out and re-engage the customer. Send a reminder encouraging your customer to return and complete the transaction. Keep in mind that the abandoned shopping cart situation can be applied beyond e-commerce situations. Any incomplete process--like membership sign-up, survey completion or white paper registration--represents an opportunity to reach out to customers.

2. What pages do they visit? When you know a customer is conducting product-specific searches on your site, you are closer to a sale if you follow up with an e-mail message that includes additional product information, or incentives to related products or categories browsed.

3. When do they visit? When customers stop regularly checking your site or, at the other end of the spectrum, do so more frequently, consider changing your messaging. Offer rewards to loyal customers who visit often, and encourage those who haven't stopped by in a while to come back for a visit.

4. Where are they coming from? Depending on your Web analytics implementation, you may be able to identify what site an e-mail customer visited just before arriving at yours. Were they checking out the competition? If so, be ready to respond with your most salient sales message. Customers who come to you from a partner's site can be sent messages that reinforce the value they receive from the partnership.

5. Why do they do what they do? By pushing e-mail demographics such as age, gender, occupation, income and geographic data into your Web analytics program, you can learn what product categories and pages are currently appealing to your demographic segments rather than relying strictly on past response and educated guesswork.

It's fairly easy to see that in order for these tactics to be successful, e-mail and Web analytics programs must be able to smoothly pass data between applications. In the past, companies were forced to cobble together these connections on their own. But today, more e-mail service providers and Web analytics vendors are teaming up to make integrations a smooth process so marketers can focus on campaign design, rather than playing middleman between their vendors. As a result, the ability to craft highly-relevant e-mail messages leveraging Web site data has never been easier.