I am re-designing a product site, and the client insists on having a FAQs section. I originally placed it in an area of low prominence on the site, but now the client is questioning it. What is the value of a FAQs section and how prominent does it need to be in the navigation on a product promotional/educational site?
Although I think that yisela is right, IMO FAQs are defective by design, DOA.
From a personal experience, I find FAQs quite useful, specially in services websites (and essential in the case where there are fees and legal issues involved). Advantage is, a FAQ page allows to anticipate questions, which can be translated into spending less time on mails and phone calls, and saving the users time spent hunting for answers. They are quite popular so don't underestimate how many visitors will use it.
Some reasons why a FAQ might go wrong:
You say you are doing a redesign. Do you have any statistics about previous usage, if there was one? Not all sites need a FAQs page, it depends on the product and how redundant it can be to have one. Does your client have the contents already thought and written? Reading them would be the best way of knowing if you need this page. It's users who tell if a FAQ question is needed.
There's not much to loose by adding a FAQ to the site, but why adding something that is not needed? That goes against the "principle of simplicity" that we designers value so very much. If you do, make sure you gather the right questions and you use a good format for it, that enables the user to hop between questions without loosing where they were.