i too have wandered around the theory that someone is making them to make a profit off of them. but you have to realize the implications...
first off, you need a large group of people to pull it off in a short amount of time, that's pretty much a given, unless you have some sort of high technology that will help you (which the magnetic radiation left behind suggests). either way, you need loads of money (unless the people are volunteers... maybe a cult of some sort??), and the money people are making off of pictures of them doesn't seem like it would suffice.
secondly, you would need a master artist to organize such an event. i have to admit, i was in the marching band in high school and we did some pretty crazy shapes on the field. but there were 120 of us. most crop circles are around the size of a football field (some even larger) and the pattern of overlaying the crops (which can be seen in the crop circle pics by the way the sun shines on them) is extremely intricate and precise. they get into that in Gazecki's movie.
you gotta admit here... scientists have used all sorts of instruments to determine their geometric perfection and have come up with very slim chances (like one in 46 million! see:
http://www.dcccs.org/ccff.htm last paragraph on left-hand side) that the geometrical accuracy could have happened by coincidence.
also, the radiation hasn't only been found on one or two of the formations, it's a common occurance. (for stem node and radiation info see:
http://www.diagnosis2012.co.uk/blt1.htm ) stem nodes don't just melt, they explode! what's causing this occurance??
so whoever is making them isn't just some schmoe, it's someone with access to a lot of technology.
there's also the occurance of white balls of light around the formations and in other fields. they've been recorded, and Gazecki actually shows a few of them in the documentary. pretty impressive as people are clearly seeing the balls of light from different positions on the land. in one of the videos, you see the ball of light pass by a tractor and the tractor stops to look at it. another one, the ball of light comes out and two black military helicopters come flying up to look at it. this is strange phenomena we're dealing with here...