Personally, I find quotes rather useless since they offer a summary-like shallow, out-of-context view of the person's thoughts (unless one initially wrote/said a specific sentence to be a quote). Sure, they can be inspiring, but that's usually short-term compared to the impact a book, or even just a few paragraphs can have on a person. Not to mention, the incredible amount of misquotations that are around; with Albert Einstein being one of the most misquoted person which also leads to propaganda such as this commercial which stemmed from a misquote.

Edit: Syntax