A New York Times article on blogging and hits quotes David L. Sifry, co-founder of Technorati:

Linking prolifically gets links . . . It sounds counterintuitive, but by being generous with links, you're contributing a significant amount of information to your readers.

About six months ago I was trying to explain the same concept to a couple friends—that the more sites you link to, the more link back to you. "You know," I said. "It's like that Magic Penny song."

They looked at me blankly.

Is it just a Unitarian thing? At my church, all the little children learned the Magic Penny song. It goes something like this:

Love is something when you give it away Give it away Give it away Love is something when you give it away You end up having more

It's just like a magic penny Hold it tight and you won't have any Lend it, spend it, you'll have so many They'll roll all over the floor