Seems like a brilliant marketing idea to me - if the publishers aren't doing it on purpose, they ought to be. Have the book tour a week before the public release, making the book available at the stores on the tour even though it's before the formal release date. It compensates stores for hosting the tour (by increasing local sales) and encourages them to promote it locally, which can only help for PR for the book in general.
Not sure if their contracts with sellers like Amazon or even just other bookstores that aren't hosting a tour would allow them to do that or not - but it's a great idea. I remember Talon of the Silver Hawk had a few copies with an extra page in them that Ray had hand-signed - I brought a copy (without that extra page) that I'd bought from the UK to a US bookstore signing, found one of those copies on the shelf, and bought it, too. Wish I could afford that kind of trick these days...!
