Courtesy of winterspeak, I found a blog of stock "recommendations." This one is particularly insightful.

Pillows are most often used by consumers for sleep-assistance purposes although they can sometimes be used for back support and/or playful fights in sorority houses

The optimal Full Pillow Equivalent (FPE) to Human Head ratio is approximately 1.0x

Pillow pricing is directly proportional to the average number of frills per pillow as well as the number of fabric colors per pillow. Pricing is generally inversely correlated to the utility and comfort of a pillow.

Some of these conclusions are surprising given the current state of the pillow market. For instance, in the US, FPEs per Human Head are running at almost 3.4x vs. the 1.0x optimal level. Note that this estimate includes almost 6 decorative pillows per household (or 1.2 FPEs)

Meanwhile, FPEs per Human Head are approximately 0.1x in developing economies such as Malaysia and Zimbabwe and around 0.6x in China, the world's most populous country.

We feel strongly that these trends will converge in the long term with the US (and Europe, to a lesser extent) reducing their consumption of frilly, non-functional pillows and developing countries upgrading from rocks to pillows for head support. Our surveys of starving third world citizens find that pillows run fifth on desired items following only clean water, freedom, blond hair and Pampers for the kids. This presents an attractive investment opportunity.

I predict this will show up with witty sidebar comments in "Investment Houses Know Worst" by Gnat Lileks in 2037. Elder statesman of radio Hugh Hewitt will flog it and get it to #37 on Googlezon, just below "The Curse of the Colavito" about the tragic loss two years in a row of the Indians to the Cubs in the World Series. Its cover will simply have a number on it: 89.