Overclocking RAM

how do you overclock ram? is it worth buying 2666mhz ram if i'm not going to overclock it? 

http://www.amazon.com/gp/product/B008YAI6IQ/ref=gno_cart_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

is this ram faster than regular ram without overclocking? Can i use it with the asus z87-k motherboard and the intel core i7 4770k?

it's a total waste of money and effort, you'll never see a difference