Hurdle: people are too cynical, especially regarding things that are exchanged via email. People have become accustomed to all things around email being free. You might have a small shot with an older demographic, but even that might be too hard. I noticed a commercial the other day advertising a "special device" that allowed you to get free tv! It was simply a digital antenna you can buy from anywhere, but this was packaged and marketed as a some sort of secret device that you were missing out on.