long tail

noun2

1. •
   Sales made for less usual goods within a very large choice, which can return a profit through reduced marketing and distribution costs.

   • What’s really amazing about the Long Tail is the sheer size of it. Combine enough nonhits on the Long Tail and you’ve got a market bigger than the hits. — 2004
2. •
   The tail of a distribution that represents the rare occurrence of extreme values.