People at several online retail sites that I've spoken with say that IE6/7 clicks and conversions are proportionally better than other browsers. Nobody seems to know the reason. Maybe people are buying stuff from crappy corporate XP systems on their lunch hours, or perhaps it's computer-illiterate octogenarians spending their Social Security checks.

As another sorta-related data point, I do know that back in the late 1990s the AOL users also clicked and converted at a higher rate than the Internet in general.