Last week, I was writing a sales letter for a client and suggested that we have interested recipients opt-in for a checklist on buying the type of insurance that she was selling—the things they really should look at to make sure they’re getting a policy with good coverage. She loved the idea of the checklist but asked why we didn’t just send it with the letter?

Makes sense, right? If you’ve got something free to offer just send it along. But it’s actually much more valuable if you don’t.

I started my response with simple economics—there’s no point in printing and mailing something that a large number of recipients may not be interested in. But moved on to the real reasons I advocated this strategy: capturing email addresses.

1) The first and foremost marketing goal of any business should be to build a list you can market to over time. Unfortunately, many business owners don’t find out how important it is to build a good list until they go to sell their business—-and the buyer suddenly loses interest because they haven’t bothered to build one.

A good list is a valuable asset to a business because it allows you to keep in touch while prospects make their buying decision, educates clients about other services you offer, and reminds both that you’re still around when they suddenly need your services. Most of the time, people won’t bother looking for the card of the person they met three months ago—-they’ll just start looking somewhere else.

2) You can gauge interest. Obviously, the hottest prospects will read the letter and say “Yes, I need to talk to her right now” and they’ll skip getting the checklist and just contact her for an appointment.

But more people will say, “Yes, this is a good idea, I’ll get the checklist and start looking into it.” So at least you know how many warm prospects you have.

3) It gives you a fool-proof way to follow up with the warmest prospects. By having them send an email or sign-up online with an email address, you can set up a series of autoresponders. Autoresponders are emails you set up ahead of time and schedule to go out at certain times or certain intervals. So even if you get sidetracked from following up on the letter (which I do not advise, but we’re talking reality here), they’re still getting little nudges from you. These aren’t sales-type emails—-they’re more helpful in nature.

So the first autoresponder email will send them the checklist. Then maybe the next one goes out a couple days later to make sure they received the checklist, another to elaborate on a point on the checklist, another with a relevant tip, etc. over the next couple months.

4. It can also help target your follow-up efforts. Ideally, you should follow up with everyone several more times. But say you hate making phone calls (like me). On a small list of fellow members like she’s purchased, you could probably identify the people who opted-in by their email address and make sure you at least called those people. Or look for them at the next meeting—-not to give them a sales pitch—-but just to strike up a conversation. Let them get to know you a little better.

So what do you think–which would you rather do?