The problem here is that few people (maybe you have, and if so, awesome) actually go to a bookstore and read a *whole* book before they decide to buy it. Where do you draw the line there?
"Wow, the butler didn't do it. That sucks. No sale."
Most people might read the back cover, maybe the first chapter, read a few reviews online, and decide. Especially if they've read other works by that author. But the whole book?
I'm betting that if you were able to listen to clips of every track on an album, say, 30 seconds worth, that'd be a reasonable compromise. Amazon does this now, and some brick and mortar stores let you listen to a CD before you buy it, in store. It's probaby a "safe bet", to use your gamble analogy, to assume that if 30 seconds out of every track is stuff you don't like, the other 3 or 4 minutes of each track may also not be something you'd like.
The bigger stores might only offer some of the "top 5" albums, but there are some smaller, locally run stores near here that will let me listen to an album in the store for ten or 15 minutes and I can decide if I like it. If I don't buy it, the retailer takes a loss on that CD because he might have to knock a few bucks off if it since it is opened, but I'm pretty sure I spend enough in there to make it worth his while.