OK, so a guy made a Web site called Tab Closed Didn’t Read to post screen shots that hide their content behind various kinds of overlays demand that users take some action before proceeding. He’s written a followup blaming the problem on over-reliance on analytics, mainly because some people justify the use of these intrusive calls to action by citing analytics. Anyone who justifies this sort of thing based on analytics should be sued for malpractice.
You can measure almost anything you like. It’s up to the practitioner to determine which metrics really matter to them. In e-commerce the formula relatively simple. If you’re Amazon.com, you want people to buy more stuff. Cart adds are good, but not as good as purchases. Adding items to your wish list is good, but not as good as putting them in your cart. If Amazon.com added an overlay to the home page urging people to sign up for a newsletter, it may add newsletter subscribers, but it’s quite likely that it would lead to less buying of stuff, less adding of stuff to the shopping cart, and less adding of items to wish lists. That’s why you don’t see annoying overlays on Amazon.com.
Perhaps in publishing, companies are less clear on which metrics really matter, so they optimize for the wrong things. Let’s not blame analytics for that.