So you've got a giant database full of people who have purchased red rubber balls from your company, and you want to start a rubber ball newsletter. It would be so easy to simply export that customer database into the seed list for your new newsletter, wouldn't it?

As Yoda once said, "Once you start down the dark path, forever will it dominate your destiny."

As easy as it would be to give your newsletter a running start, force-subscribing customers to anything is a great way to get them to run away from your company, screaming.

I'm not kidding about the screaming part. People love to talk in online forums about how Company X spammed them and how they'll never do business with them again.

Don't forget, when someone spouts off about being spammed on a blog, message board, social networking site or other online community, those comments tend to stick around. And we all know how well blogs and community sites tend to be treated by Google and other search engines. A negative comment about spam out in the blogosphere, especially if other bloggers link to it, can be devastating to a brand's online reputation, not to mention natural search engine results.

Like it or not, a newsletter needs to be built organically. Perform an audit of customer touchpoints, from your website to your advertising to even your email signatures. You'll find plenty of opportunities to get customers and prospects signed up through an opt-in process.