I read this a while ago and enjoyed it as a quick light read. The only thing I couldn't get my head round was when it was set, as it follows a relationship over 30 years, but none of the technology changed. The couple were IM/emailing in their teens, but still doing 30 years later. There wasn't email 30 years ago, but if it was started in the present, then surely 30 years in the future how we communicate would changed. Sorry, it bugged me a little.
I had previously tried to read PS I Love You but found that too sentimental and felt like it was trying to hard to pull on the heartstrings it put me off. I gave up on that my the 3rd chapter.
I quite like books that tell the story through letters, emails etc. I can't remember what they are called... Anyone? Another in the same style I've enjoyed in the past were Mag Cabott's Boy books & also Holly's Inbox. They are great for when you need some quick, not at all taxing, fluffy but you feel it's tiny bit more substantial than magazine.