I just did this and so far have gotten one backer from it but I think this is a great idea, obviously you couldn't do this for the entire goal of a project because you wouldn't gain anything but I think it's a great way to get attention and gain backers. My project got off to a pretty good start but I'm having trouble keeping momentum going and getting the word out to people so I think this is a great idea. you give a dollar or two and gain a dollar or two, money wise you don't really gain anything but you get more backers and that shows that more people are interested in what you're doing.
https://www.kickstarter.com/projects/20 ... hyperlightthis is my project and I would love to do this with anyone that wants to, I'll pledge up to two dollars to anyone that does the same for me. just send me a message on Kickstarter after you've pledged and left a comment and I'll do the same within an hour or two, as long as it's during the day, if not I'll get back to it within 24 hours.
Another benefit is that lots of people only back projects from someone that has backed others already.