I'll call complete bullshit on it. When you eliminate a door, it becomes 50/50. Surely someone with a bit of programming knowledge could write a very simple program to prove this. You'll get the same probability of winning either sticking with the original pick or switching.
Fuck, not complete bullshit, http://en.wikipedia.org/wiki/Monty_hall_problem#Increasing_the_number_of_doors The wikipedia version of it helps you to uhderstand it much more easily. I've linked to one of the aids to understanding, specifically, increasing the number of doors there are.
This is the first pornsite I've found in years that I'd actually advertise to swarmers. When you first load it up, it looks just like every crappy scam site out there, except that it's real. It's huge, it's updated constantly, there's no spam, no popups, and no bullshit -- and it's completely free. When you sign up through that link above and respond to the confirmation email, I make a bit of loose change.
See what other swarmers have to say about it. People love this place, so I feel fine about sending you there and am confident you will enjoy boners.