The Value of Linking

By having a legitimate link to a piece of content one can immediately enjoy and experience it. For example I can say: "Jenna Drey's single 'That's What They All Say' is very nice, follow the link to download it.", or "Austin Acton's 'Two Point Six' is lame but still cool.", or "Pearl Jam made their new single 'Life Wasted' freely distributable. Here's the torrent.". Etc. (These are all legitimate downloads).

This is much better availability and accessibility than having to go to the store and buy it, or even buy it from an online store. And it an excellent publicity.

For more information consult Paul Graham's essays "Web 2.0" and "What Business can Learn from Open Source.