It's custom in most stores to include the product in the box when it is sold to you.
We think of it as fair exchange, even if the price might sometimes be high.
A man in the United Kingdom, however, wondered about the equity of a transaction, when he bought an iPad from retailer Tesco.
You see, he had a small issue with the iPad: there wasn't actually an iPad in the box. Instead, as The Telegraph reported last week, there were pieces of clay.
Colin Marsh, who owns two bakeries, went back to Tesco, but his pleas fell on clay ears.
While he remonstrated about spending 470 British pounds (around $757) for a non-existent iPad, the staff reported him to the police.
A quick check had revealed that the iPad Tesco believed was in the box had already been activated.
The police called Marsh and invited him for a friendly chat. When he arrived, he was put in a jail cell for three hours.
Indeed, it took him two months to get allegations of fraud dropped.
You might imagine that Marsh -- who had bought the clay iPad for his 11-year-old daughter Maggie -- wasn't enamored of his experience.
He told The Telegraph: "You just can't treat people like that. It's absolutely disgusting. I've not even had so much as an apology from Tesco. It's disgraceful."
This all happened during last year's holiday season.
Stunningly, once the news began to reach the ears and fingers of the media, Tesco appears to have offered an apology -- although some might see it as slightly rocky.
A Tesco spokesman told The Telegraph: "We were very disappointed to learn that the product we sold to Mr Marsh had been tampered with. We would of course never knowingly have sold it to Mr Marsh and we apologize sincerely for the problems this has caused him."
One translation of this might be: "Yes, we didn't do too much checking. He looked like a fraudster to us. It's not our problem that the police arrested him."
The store told the police that the iPad had been activated in Marsh's name.
It took two months for the authorities to notice that it had been activated in Wales, whereas Marsh bought it in Whitstable, Kent.
These two places are some 200 miles apart, which might have offered a clue as to Marsh's story. Why it took so long seems now to be clearer.
As the Kentish Times reported, the store allegedly gave the wrong information to the police.
More Technically Incorrect
Another mystery is how Tesco managed to sell a customer an iPad box with pieces of clay inside it. It couldn't be that the company has resorted to buying iPads in McDonald's parking lots, could it?
In fact, it may be related to fraudsters in Canada who bought 24 iPads removed them from the boxes and then returned them -- clayed down -- to large retailers.
Some might conclude, therefore, that Tesco accepted a return from fraudsters, but didn't accept the word of someone who wasn't a fraudster at all.
Marsh finally got his 470 British pounds back, but that hasn't exactly made him feel justice has been done.
Though he still sometimes goes into Tesco, he told the Kentish Times: "Even now when I go in there I feel uncomfortable because I think the staff are looking at me and thinking 'he did it.'"
One person who might have sympathy for Marsh is the woman in Texas, who last year bought an iPad at Walmart and found it contained only yellow notepads.
We must close, therefore, with the same warning we'd give to anyone buying any sort of gadget. Please open the box before you leave the store.
Otherwise, you know, you might get put in jail.