Free?

The results seem to say that we're willing to do things we wouldn't normally do if they weren't free. When something is free, we get excited and don't want to pass up the opportunity. Dan suggests that the way to beat this is to ask yourself a simple question: if this "free" thing was extremely cheap (like $1), would you buy it? If not, it's a good sign that you might want to pass up on the free opportunity.

from Lifehacker