When it comes to direct marketing, the oldest rule in the book is that choosing the right list is the #1 ingredient in a successful campaign. Nowhere is that more the case than with broadcast e-mail.

Because the direct mail list industry has been around for years, there's a certain consistency to the way most direct mail lists are sourced. One magazine list is much like another, for example, at least in terms of currency and data reliability. The same can't be said for e-mail lists, however, and indeed there's enormous variance between the way different e-mail lists are sourced, maintained and managed. We've often deployed e-mail campaigns for clients where the gap in response between different lists, even lists that on paper look very similar, can be quite dramatic.

What complicates the issue further is that most e-mail list owners control the broadcast function. Broadcast capabilities vary widely, and this can impose constraints on how you deliver your message - the number of subject lines you use, for example, whether or not you're able to "split" the file into multiple versions with different copy going to each test cell, whether the copy is plain text or HTML, whether you're able to track how many people opened the message, and so on.

There's another old direct marketing rule of thumb that says: "Bad creative to a good list will always outperform good creative to a bad list." Updated for the times, perhaps it ought to read: "Text to a good list will always outperform HTML to a bad list."

Unfortunately, it's easy to succumb to the lure of rich media, and gravitate to those lists and list owners who offer the capability to deliver your message in HTML format. Based on our experience, however, it would be a mistake to make that your primary consideration. In fact, the basic principles for choosing the right list haven't changed much: