There's a lot of meat on the long tail
Tastes like chicken.
The long tail is the idea that less-popular items, in the aggregate, constitute a large fraction of what we buy. And that the web and other digital technologies make it easier for us to find niche stuff, and cheaper for sellers to make, market, and distribute it.
These pieces can combine in interesting ways.
Charles Platt mentions (in passing, the article is about the inventor of the neutron bomb) the main problem at the skinny end of the long tail.
He told me that I was the only reader who had bothered to write to him about his book, which did not surprise me, since print-on-demand publishing means precisely what it says. It prints copies only if there's a demand, but it never creates a demand, and therefore it is unlikely to print many copies.
Tom Bozzo describes how several long tail elements — digital creativity, empowered customers, mass customization — combine to realize the coolest frickin' idea in the world.