Paul Graham on web communities.
So readers will willingly buy words delivered in different forms, but it depends on a combination of price, convenience and timing. Sometimes they borrow books from the library. Sometimes they buy books. Sometimes they will even pay for access to words on the Internet — but more often than not, they balk at paying for words on the web. […]
“Read for free, pay for print or stuff,” on the other hand, is a model that can, and does, deliver revenue.