Market segmentation traditionally assumes that people can be segmented into groups that can be separately marketed to, based on their different product needs. But suppose, as often happens on the Web, the customer arrives in your midst—on your site—before or she has any inkling of his or her different product needs. And suppose what happens next—to that customer on your site—will strongly influence how that customer ends up perceiving his or her particular product needs. Now, what is your segmentation strategy for this Web stage of the game?
For that stage, I endorse the segmentation approach advocated by many theorists of Web design: segment your visitors by (a) what is unlikely to change as the result of their visit, e.g., lifestyle profile and prior level of experience with your product, and (b) their content preferences.
Some aspects of their content preferences will be unaffected by their visit (e.g., a general preference for graphics over statistics), but other aspects will be affected (e.g., if the buyer learns more about which features are important to a product category, their interest in which products possess those features will increase). In particular, segmenting your non-current-customer Web visitors primarily by their content preferences seems to make a lot of sense.
This way, your web designers and copywriters can generate Web pages and content that appeal to the persona, defined with heavy reference to their content preferences, that represent those key segments.