I think companies in general should have a Order list and each item should be PROPERLY checked its the right one before its boxed and despatched. I know how it is cos most just whack it in the box and just tick yes, yes, yes, yes sign and time and date and off it goes....
Then this cost the company in question £20-30 instant loss and plain headache for all the companies, not to mention alot of time loss for all.
The smallest things can be done to fix this, ie on the order list leave a space, force the warehouse picker to write down the product code/serial. Am sure theres other way too, Ebuyer I think once moved onto a weighing system so if the order came in so did the weight and if it was picked and boxed and it weighed wrong they knew something was missing/incorrect... but I think they got rid of that system.
Clever thinking but I think easier/cheaper soloutions are already out there... its proberly called common sense for one thing.