This article is important.

“…a digital jukebox company whose barroom players offer more than 150,000 tracks…”

“….The average Barnes & Noble carries 130,000 titles. Yet more than half of Amazon’s book sales come from outside its top 130,000 titles. …”

“… successful businesses on the Internet are about aggregating the Long Tail in one way or another. Google, for instance, makes most of its money off small advertisers (the long tail of advertising), and eBay is mostly tail as well – niche and one-off products. …”

Go read it.