We’ve linked to stories about BookMooch “ a website that allows book lovers to swap books free of charge “ before, but here’s a more in-depth look at the site and its creator, the young high tech millionaire John Buckman.

From CNET.com:

Even though BookMooch is free to members, the site generates an estimated half-million dollars in annual book sales for Amazon because of a browser plug-in called the Moochbar, which matches members’ book wish lists to Amazon’s retail inventory. For every 25 books swapped on BookMooch, at least one person buys a new book on Amazon through the Moochbar. BookMooch collects 8.34 percent on each of those Amazon sales.

“We’re making money by accident,” said Buckman, who spoke recently at a technology luncheon near his home in Berkeley, Calif.

[…]

What’s more, within the next nine months, Buckman expects to have the inventory of books–distributed among its members–that would rival that of the largest book wholesaler in the United States. BookMooch now has an inventory of about 480,000 books among its 70,000 trading members, but at its growth rate it should rival Ingram Book Company’s 1 million books by early 2009, Buckman said.