I had heard about it from my doctor who had lost a lot of weight on the program. I kind of wrote it off, said I couldn't afford it right now, etc. Then nearly 10 months later, I saw a coach do a Living Social deal. Essentially it was for the upfront cost (it really wasn't IP she was advertising... it was a food based diet), but just seeing it again at that time made it click.
So I bought the "deal" and set up an appointment for the week after my sister's wedding. Talk about a lot of before pictures!