DVD's make the world go round

Going through my dvd collection I realised that roughly ten percent of them were not mine. Further more, ten percent of mine were missing, presumed lent. I’ve asked around and compared stats, and this seems to be average. A ten percent changeover range, a buffer zone I guess. It would probably apply to videos as well, but they are so ugly and clunky I think it would be better to ignore them for now. Considering most people would borrow one or two dvds at a time, lets say three at most, but rarely, that would give us an average of 1 friend borrowing 1.5 dvds at a time. So lets say I have 60 dvds, ten percent of 60 is 6, so 4 friends have borrowed dvds from me. And if they have the same buffer dvd zone 4 of their friends will have borrowed dvds. Surely it would be possible to link everyone in the world through their dvds? I call it the six dvds of separation theory.