[wpietri]

Your reaction is normal for a late-majority adopter [1]. But early-stage startups are looking for the innovators and the earliest of the early adopters. When those people get to the point of saying, "OMG, I want it!" they will indeed sign contracts or pull out a credit card.

The point of asking people for money is exactly to separate the people who really are early adopters from those who are just enthusiastic.

A great example is Kickstarter. You may be unwilling to buy a product based on little more than a dream, but plenty of people are willing to take a gamble on something risky when they care enough about it. The rest of us wait until the product has come out, has been reviewed, and have friends using it.

[1] http://en.wikipedia.org/wiki/Diffusions_of_innovations