"Customers Who Bought This Item Also Bought" on Amazon is extremely useful. In one case I saw an author's titles continually pop up for months, looked him, found his blog, realized he was a genius, an then end up buying everything he wrote.
Pretty much everything I read now comes from that process.
There is a networking effect in place here. The first is from Amazon, the second is from the blogosphere/wherever authors are interacting.
One thing is for certain -- authors absolutely need to have good blogs and write frequently. Some of my favorite authors have infrequently updated blogs or Twitter accounts. Unfortunately I forget about them.
"Customers Who Bought This Item Also Bought" creates chains if you dig deep enough. You will not be limited to a single pool of books (or music for that matter.) But, I find its also important to hand search the authors (or musicians) that come up for rarer and often just as meaningful work.
I like the ebook process of selection much better. I hear about books and authors from friends, blogs and discussions like this. I then go to Amazon, read the reviews, look at the kindle price (I don't pay more than $10 unless I am already familiar with the author) and click on the Buy Now button.
ebooks may blur the lines between the genres, but is this really a bad thing? Is there any reason why a book can't fit into several categories? There isn't. Genre was a way for stores to organize their inventory, and now that shelf space is no longer a premium we can use better methods to find new reading material.
Actually, since buying my Kindle I have read more than ever and find it hard to keep up with my reading list.