I’ve been thinking about how personas can be used in marketing for a while now.
This article by Steve Mulder explains really well about the role of personas in marketing, and how they can link to market segmentation.
Personas and segmentation are complementary tools to help make marketing more effective:

Where market segments help you target qualified potential customers, personas help you satisfy these people. Working together, they complete the loop by helping you generate demand and then satisfy that demand.

If you’re interested in exploring more effective market segmentation then Steve’s article is well worth a read.