Nashers
Pretty simple really.
All the good stuff like expensive perfumes, aftershaves etc. either gets pocketed by the Security Neanderthals themselves or (as we have seen herein) sold on e-Bay.
All the factory sealed stuff undoubtedly ends up on the shelves of the local 'open all hours' to the mutual financial benefit of all concerned. Who knows? It might even move only a few yards to end up in the air-side shops where flight crew and passengers are expected to replace that which has just been stolen from them at three times the price.
Who says larceny doesn't pay.