Online marketers like to segment by first time visitors, prior visitors, prior buyers, that kind of thing.
Catalog marketers like to segment by recency / frequency / monetary values.
Give this one a try. Take all of your first time buyers who purchased two items. Split those customers into those who bought from just one merchandise division, and those who bought from multiple merchandise divisions. Then measure the long-term value of each segment of customers.
It turns out that, in most cases, customers buying a broad range of products are more valuable than customers who have a preference for just one merchandise division.
So give that a try ... and if you are a web analytics expert, take a look at conversion rates by this level of segmentation!