"Tracking to a merchant is as important as the instruments on a plane to a pilot," Tom Bianco, CEO of Centripetal Management

They're invisible to most online shoppers, but analytics programs that are combing through every click they make are dictating what their shopping experience looks like.

Thanks to a proliferation of easy-to-use and affordable  -- even free -- analytics programs, a growing number of merchants are using data mining  feedback.

Merchants are utilizing the information to tweak their advertising  spending, to adjust how they present merchandise for sale and to change, in some cases in nearly real time, their promotions, prices and discounts. Data mining may dictate where on a page a product is displayed, how much it costs and a host of other factors.

In fact, some merchants say any e-tailer not using analytical feedback is likely missing enormous opportunities to boost conversion rates, lower pay-per-click ad costs and, in short, make more money.