Fake or Cake? What's your Opinion!!

It seems that a fairly new (at least new to me) and popular notion among brides on a budget is the fake cake. By "fake" I mean ordering a beautifully decorated, fondant covered wedding cake...but what is inside? STYROFOAM! Some businesses even rent these already decorated cakes for your special day. Neat idea if you ask me, who ever eats all that cake anyway? So why pay for it? Often times the bottom or bottom two tiers are made of actual cake...can't skip that classic photo op. So what's your take? Is this really a growing bridal market? Would you forgo the real cake for a potential $500 price break?