Indeed a highly interesting topic, but I'd wish that you'd put more effort into writing your own words and thoughts about this topic instead of just quoting wikipedia and a randomly-found book from the Internet. :)

Furthermore, saying that O(n log n) is a "Bad" complexity seems to be a bit off, as this is (most of the time) the best one can achieve when using sorting algorithms (par example). From my knowledge, Heap-, Quick- and Merge-Sort are the most commonly used, yet still have O(n log n) complexity.

Again, the topic seems shallow, but can actually go pretty deep, so why not try again in a more complex post with own words and ideas? :)