In a California gourmet market, Professor Iyengar and her research assistants set up a booth of samples of Wilkin & Sons jams. Every few hours, they switched from offering a selection of 24 jams to a group of six jams. On average, customers tasted two jams, regardless of the size of the assortment, and each one received a coupon good for $1 off one Wilkin & Sons jam.

Here's the interesting part. Sixty percent of customers were drawn to the large assortment, while only 40 percent stopped by the small one. But 30 percent of the people who had sampled from the small assortment decided to buy jam, while only 3 percent of those confronted with the two dozen jams purchased a jar.

That study "raised the hypothesis that the presence of choice might be appealing as a theory," Professor Iyengar said last year, "but in reality, people might find more and more choice to actually be debilitating."

Over the years, versions of the jam study have been conducted using all sorts of subjects, like chocolate and speed dating.

I suppose then that someone can do the same for channels.