This article by Gerry McGovern goes into a bit more detail on the Jupiter personalization report: Why personalization hasn’t worked. (Thanks to James Robertson for the link.)
Not surprisingly, the Jupiter report finds that personalized websites are four times more expensive to run. It also finds that personalized websites are twice as likely to attract visitors who will never pay for anything. Worse still, it finds that 25 percent of consumers actually avoid personalized websites because they fear that their personal information will be abused.
I contacted Jupiter about buying the report and they said it will be available for sale in about 8 weeks (I assume they are giving their subscribers a 2-month exclusive). It will show up on this site when it becomes available to the general, non-subscribing, public.