I'm just reading through Robert Cialdini's "Influence, Science and Practice," and wanted to throw out a particular suggestion he makes... If you give someone a gift, they are almost always obliged to give in to something. Send a dollar bill with a survey and you will get far more responses than if you promise to send them a $5 bill after they complete the survey. The Hare Krishnas hand out flowers because there is a social obligation (biological, community-driven) to respond in kind somehow - to offer a dollar or more, even if you did not want the gift in the first place. But the problem with this in IM, as I see it, is that your users don't see your gift as being of value, and you can't physically give it to them. Since they can't see you, and the gift is probably digital, the obligation is significantly lessened. How to combat this? I'm thinking of years ago, when I used to use mIRC, and Khaled, the programmer, included a picture of his face on the trial version's startup screen. That was the screen that asked you to purchase the program. I'm looking for any other ideas that you could use in a demo, a trial version, a free software, to convince users to actually pay for this or another product. Suggestions?