Want to be part of an experiment?

Question: Do free ebooks help or hurt paper book sales?
Tor is offering free ebooks if you sign up with their newsletter here. They offer a different one each week–this week is Scalzi’s Old Man’s War. (If you want it and missed it, ask a friend–the email says “tell a friend” but I don’t know if they want me to, you know, post the links here, so I won’t.) The first one was only in PDF, but this week’s is in PDF, HTML, and Mobi version (yay, my PDA is so happy!).
If you hurry, you might still be able to get Scalzi’s book. Next week’s won a Hugo (SPIN by Robert Charles Wilson).
Yes, yes. You have to get their newsletter. But they pay you to receive it–in ebooks!
And, you know, if you really like the ebook and want to do something nice for the author, then you can buy a paper copy. If you don’t want your paper copy, you can give it to a friend you think would like it, or to a library or bookcrossing. You don’t have to, but if you do you can help provide data that contradicts the idea that ebooks are the END OF DAYS FOR AUTHORS ZOMG, and maybe publishers and authors will make more of ’em, and then we’ll live in an ebook utopia. It could happen.