A few years back, a then colleague of ours gave an excellent overview of email marketing. Ranging from strategy to the mechanics of list & email design, the series elegantly captured the thinking behind successful email marketing programs. Rather than re-invent the wheel, I have shamelessly borrowed the best of his material to create a series on the benefits of a well planned email marketing program
The eleventh post speaks lastly on segmentation ideas with a discussion on performing a "lifestyle" analysis of your data will identify patterns that can be used to build customers into groups which tend to exhibit similar behaviours.
I hope you enjoy & can put to use the ideas here, as part of the larger series.