Thanks. I downloaded a sample book from B&N and was able to read it just fine. So I took the chance and bought it (since it was $7 compared to $14 on ebooks & ebookstoresony). But the purchased book says "failed to open file".
Lesson learned.
BTW, before I purchased the Libre I checked 15-20 of my favorite titles from B&N, Amazon, ebooks & sony and they were almost all exactly the same price except for one or two were cheaper at B&N. My main concern in choosing an ereader was the titles being available of what I wanted to read. Then my second concern was the price of the e-reader.
The Sony bookstore has a better selection than ebooks so I was hoping I would be able to purchase from them. I guess I will go try that. I did notice the large margins on the sample books I viewed, it was a little better when I rotated the screen.