I thought I'd use our own experience with purchasing prints and canvases as a perfect opportunity to educate others about print sizes and why they matter. (You can also learn about why getting your photographed printed in the first place is so important here.) When decorating with custom photography, it's important to be BOLD. You gotta go big or go home.
When you stop and think about how large a wall really is, you realize they're massive -- generally 8' or 10' tall by 12' or 15' feet wide. Unless you've got a collage, 8" x 10" just isn't going to cut it.
Take a look at our living room and you'll see what I mean.