Flexplay self-destructing DVDs

Has anyone else heard about these and what do you think about them? I was at Staples and they had these self destructing DVD movies and what they are is movied that once exposed to the air have about 48 hours on them to watch the movie and then they "self destruct",,,,I thought this was great since they only cost me $1.98 per movie and there is no mailing or taking a movie back. What does anyone else thing about this idea?