Goodreads- what is it good for?

I think Edwin Starr put it best when he said ‘Goodreads, huh, what is it good for? Absolutely nothing.’ Either Goodreads or war, I can never remember which.
Anyway, I visit a Kindle Board site (now KB for short) from time to time and a regular post that appears there will go something like this: ‘I’m on Goodreads but I just don’t know how to use it’ or ‘I worry that it doesn’t seem to be resulting in any increase in sales’.
It seems to me that some folk don’t really get what Goodreads is for and should perhaps pay a little more attention as the clue is in the title- it is for READERS. I write books but I read too and the interesting thing for me about books is the ideas between the covers or what they make me think of, not how many sales they produce. Now, it’s true if I was absolutely forced to be rich and famous, I’d bravely put up with it, but it’s not my whole raison d’etre, as they say in Spain.
It reminds me of an old Jimmy Carr gag which runs something like ‘I’m sponsoring a child in Africa but I wonder is it doing any good? I haven’t seen any increase in bookings…’