LOL. GOT is heavy on nekkid people because it is a cheap and easy way to attract an audience, and because nekkid people is a big part of the HBO brand, and therefore part of the justification for paying for a premium channel. I cannot think of a single GOT sex scene that could not have been shot fully or mostly clothed, with the nekkidness off-screen or implied. But that's not HBO.
Sometime last year someone did a super cut of all the GOT sex scenes through season 3. It was 16 minutes long. That's just under 1% total screen time. If the story is to be believed Fifty Shades will run twenty times higher than that (100 minutes long/20 minutes of sex scenes = 20% total screen time). Who's using sex to attract an audience here?