My grandmother wants me to go and get her a Kindle today. I can't decide between the 7" or the 8.9". She will probably use it primarily for reading but also wants to check email and facebook, stuff like that. I took my 7" to her house and she said she could read it just fine but I'm wondering whether the 8.9" would be a better choice. The only important stuff would be the screen size and MAYBE the camera (but I doubt it). Is it worth the extra money for the extra screen size?