I have a friend working in an Internet marketing company as Sr. SEO. There is a rule in his company that every SEO person or a link builder must build or get 500 backlinks per day and I hear that they are still providing better results and delivering projects on time and before time. They do target competitive keywords and less competitive phrases.
An example of a keyword would be "Electrical Installations" and "Electrical Apparatus NewYork".
They mostly work on Directory submission, Social Bookmarking and Articles. Prioritized in order.
My question is: Is over optimization really a problem? I am sure what these guys do is something called "Over Optimization"