@anim8ed
Goodreads is a book recommendation site based on social networking. I am sure they monetize by being an official affiliate sales outlet to the various book dealers with which they have links.
Interesting comment, in light of their terms of use copied below:
quote:
Main Terms
By posting any User Content on the Service, you expressly grant, and you represent and warrant that you have a right to grant, to Goodreads a royalty-free, sublicensable, transferable, perpetual, irrevocable, non-exclusive, worldwide license to use, reproduce, modify, publish, list information regarding, edit, translate, distribute, publicly perform, publicly display, and make derivative works of all such User Content and your name, voice, and/or likeness as contained in your User Content, in whole or in part, and in any form, media or technology, whether now known or hereafter developed, and to grant and authorize sublicenses of the foregoing for any purpose at the sole discretion of Goodreads.
Writer Terms
By posting or submitting any Work on or to the Service, you expressly grant, and you represent and warrant that you have a right to grant, to Goodreads a royalty-free, sublicensable (solely as required to publish the Work in connection with the Service), transferable (solely to a successor to Goodreads' business), revocable, non-exclusive, worldwide license to use, reproduce, publish, list information regarding, edit, translate, distribute, publicly perform, publicly display, and (for formatting purposes or to conform to system requirements only) modify and make derivative works of the Work and your name, voice, and/or likeness in connection with the Work, in whole or in part, on and through the Service, and to permit and authorize Users to download the Work as specified by you through settings we may make available to you on the Service.
You authorize Goodreads to sell the Work free of digital rights management under a perpetual and freely transferable license to the User.
To ensure proper payment, you are solely responsible for providing and maintaining accurate contact and payment information associated with your account, which includes without limitation applicable tax information.
end quote
There's those lovely words again irrevocable, non-exclusive, worldwide license to use - and I've never given them any approval for anything via anyone. But I don't mind what they do with the freebie books.