The recession has had a silver lining for direct-response advertisers, who found they could afford to advertise on TV in prime time rather than late at night after banks and automakers curtailed their advertising and ad rates dropped.

None of the latest crop of infomercials has been a bigger sensation than the Snuggie, which draws derision and awe in equal measure. It has been mocked by television hosts like Jay Leno, Jon Stewart and Ellen DeGeneres, donned at Snuggie pub crawls across the country, parodied in videos on YouTube, and idolized on Facebook, where the Snuggie page has more than 77,000 fans.

In the soon-to-be-published book, Priceless: The Myth of Fair Value (and How to Take Advantage of It), the author William Poundstone writes that the central principle of infomercials is what the economist Richard Thaler calls “Don’t wrap all the Christmas presents in one box,” meaning that consumers value freebies that come with a purchased item more than purchasing the same items presented as a set.