I just asked! Seriously, I emailed them to explain what I was planning, and very nearly everyone I asked said yes. In all fairness, though, these are folks I've had other dealings with - I've met them at ThrillerFest, they've been guest speakers at the writers discussion forums I oversee, or they've been on the faculty at my writers' conferences. Also, only a couple of the more tech-savvy recorded their own clips - I gave everyone the option of having me record them with my video camera at ThrillerFest, and as you can see from the clips, that's what most of them did.
One thing about mystery and thriller writers - they're some of the nicest, most generous people on the planet. I bet there are many, many authors who'd be willing to record a short clip.
Karen, I just got back from your virtual party and it worked. I'm very impressed with the idea. It will be liberally stolen by most of your friends and probably a few people you don't know. What a great idea. It worked too, darn it, now I've gotta go get my credit card and order the darn thing. I'm putting in for a signed copy too, by golly.
Congratulations on an effective promotion and finally getting the book launched.
I'm also in the middle of an online book tour too--lots of fun and I think it's helpful for getting your name and your book in front of people. Today and tomorrow I have a booth at the Apple Festival in my town. Expecting at least 20,000 people. I usually do well. We'll see how it goes.