Nitrogen in Tires

I was doing some research to find out why it is becoming more popular to fill tires with nitrogen instead of just air. The results were interesting. It seems that the theory is that nitrogen is supposed to replace so-called skinny oxygen molecules with fat ones. That would mean the air would have a harder time escaping from the tire, and it would be at its optimum tire-pressure for a longer amount of time. The other benefit that nitrogen in tires is supposed to have is reducing or eliminating moisture in the tire. As these benefits are tested over time, more and more people might start inflating with nitrogen instead of just air.