The ROI of the Bellagio Fountains

On hols in Vegas a couple of weeks ago [yes, that was a mild gloat], we went for dinner at The Bellagio to treat ourselves and I was amazed at how many people had come to watch the water fountains. I started to wonder what would happen if the clever chap who came up with the idea of having a choreographed water fountain show every 15 mins at a hotel in the desert was asked to prove the ROI of the fountains before s/he was allowed to commission them.

You can imagine the discussion:
Designer: "I want to have a huge pulsating burst of water every 15 mins, timed to a variety of music."
CFO: "you do know we're in the middle of the desert where water is very scarce?"
Designer: "yes! It will be an amazing installation"
CFO: "What will we get in return?"
Designer: "People will come from miles to see the fountains"
CFO: "How many people and how much will they spend?"

I guess my rather facetious point is that you can't forecast an ROI for everything, sometimes you just gotta go with your gut and do something special.