Reciprocity Study

I am be the only one, but I really have no idea what the actual point of the study was. What does it really show us about the Internet as a persuasive tool. The study was based on the idea that that if someone helps you out, then you will be obligated to reciprocate. Well, it seems to me that in the case of a campaign for example, if their website is particularly easy to use, you would be obligated to return the favor to the campaign, not the computer or the website. So it seems like this was all done where a study not involving a computer would have been just as effective in proving the point.