Web Analytics is a new & fast-growing technology category which helps understand in detail where website visitors come from, what they look at and - in an e-commerce context - what they purchase.
It's also very technical - requiring folk to understand "log files" and "page tagging". (See article). You know the market is real when M&A activity is happening and this week Google bought Urchin and Webtrends completed an MBO.
Screen Pages already offers a strong analytics package as part of its managed e-commerce service, but I fear it is an unsung virtue!