Why don't they just charge for their iPhone app and use a fremium model? I'm blown away that they can't figure out a way to monetize 2 million users. If they do

Why don't they just charge for their iPhone app and use a fremium model? I'm blown away that they can't figure out a way to monetize 2 million users. If they don't get acquired I will be very shocked. I pledged that I am willing to pay, it's a bargain for how useful their service is. Also, why don't they just use kickstarter.com??