If you're thinking of providing a demo or limited-use version of your software, pay for the bandwidth and host it yourself. It is an enormous waste of time for potential customers - not to mention that it's incredibly insulting - when you host at one of the big "make you follow 7 links, then sit in a queue, and then download a potentially tampered executable at a reduced speed" 3rd party file hosts that seem to be all the rage these days.

Bandwidth is relatively cheap nowadays, coming in at less than 8 cents a GB at many providers.

What does this have to do with social proof? Well if you host your demo or lite version at one of the aforementioned file hosts, my immediate presumption is that a very tiny percentage of users actually pay for the software: What else could justify such an abuse of clients?

Given this obvious conclusion, the power of social proof pushes me to lean against purchasing it either.