Get Thee Behind Me, Zappos

Lately every website I open has gorgeous supple leather pumps of a kind I perpetually covet on display in the sidebar. "Lookee how beautiful we aaaaaaare" they seem to whisper, "you know you want us." Is the whole internet conspiring against my quest for moderation, my determination to cease buying essentially the same pair of shoes again every year I have asked myself? Yes, as it turns out. Now I understand all: The Web's New Gold Mine: Your Secrets.

Tracking technology is getting smarter and more intrusive. Monitoring used to be limited mainly to "cookie" files that record websites people visit. But the Journal found new tools that scan in real time what people are doing on a Web page, then instantly assess location, income, shopping interests and even medical conditions. Some tools surreptitiously re-spawn themselves even after users try to delete them. These profiles of individuals, constantly refreshed, are bought and sold on stock-market-like exchanges that have sprung up in the past 18 months.

So it's not my imagination.