Prosumers

http://en.wikipedia.org/wiki/Prosumer

Refers to consumers that produce their own media content

Participatory Culture

http://en.wikipedia.org/wiki/Participatory_culture

A culture in which consumers actively participate.

Henry Jenkins
http://en.wikipedia.org/wiki/Henry_Jenkins

The Long Tail

The long tail refers to the possibility of making a greater profit from the sales of niche products as apposed to the profit from the larger number of sales of the most popular goods.
This is due to the online age which has meant that physical space is not necessary in order to store goods. Examples include online stores such as Amazon and iTunes.