FAQ is an acronym that means Frequently Asked Questions. You see, computer nerds are relatively lazy people that hate answering the same questions over and over again. In fact, it drives many of them positively batty.
Philip Greenspun a professor at MIT wrote in one of his web publishing books, that he would answer any question twice. Then he would put the question and answer in the FAQ file, because if there were at least two people that wanted to know the same thing, there were bound to be hundreds more just wanting to ask the same thing.
I'm writing this because although many companies know that it is important to have a Frequently Asked Questions page, most have a "We Wish Our Customers Would Ask These Questions" page. The two are not the same thing. FAQ pages are for frequently asked questions, the rest of your website is for everything else, including things you wish people knew about your company.
Having anything but frequent questions in a FAQ page makes the FAQ page bloated and less useful to people who realize millions of people are on the internet and their particular question has been answered a million times already.
As you can see, I don't have a FAQ page. This is because no one ever asks me any questions. My website covers everything that people want to know from me already.