When it comes to mailing lists, it is a truth universally acknowledged that the best list is the one that grows organically from past dealings with your own happy customers.

If you are not in the enviable position of possessing that kind of organic list, you still have options. Renting a list is one possibility, but it is a strategy that garners a great deal of skepticism from marketing professionals. That skepticism is not always justified.

The negatives are well known. The most obvious problem stems from the fundamental fact that email marketing is permission marketing. In the best organic case, readers have given explicit permission to receive your messages. In the rental case, the reader may have given permission to someone, somewhere long ago, but that permission was not given directly to you, and the reader may have no recollection at all of when, where or why he signed up for future communications. That unexpected email is the kind that is unlikely to be opened.

In the worst case, a reader receiving an out-of-the-blue email from an unknown source will report it as spam, an act that can limit your ability to send messages in the future. Readers will mark your messages as junk mail, ISPs will take note, your messages will not be opened and your bounce rate will escalate. Your reputation is damaged and, if the problem persists, it may ultimately become difficult or impossible to deliver email to your existing customer base.

Despite those daunting negatives, renting a list can be a good choice for the right business and the right list, provided that you bear those qualifications in mind.

The greatest benefit of renting is the most obvious: If your own efforts at organic list-making are not bearing fruit, you get a ready-made list of prequalified leads with valid email addresses.

All lists are not created equal, however, and it pays to do some homework so that you can judge the quality of the list before committing to a broker. The more you can define your own specifications, the better you can communicate your business needs. At the same time, the more you know about the list, the better you can judge its suitability for your goals.

Look for the attributes that matter. A list drawn from trade publications or from newsletter subscribers is generally a better list than one that resulted from responses to a free offer. People who have made purchases can make a good list, but look closer. Did they purchase something similar to your products? Do their demographics match those of your own customers?

In other words, this is not a project for the lowest bidder or an impulse buy. If you take time for a long, hard look at both the list and your own objectives, a rented list can help jump-start a productive email campaign.