Brilliant! Because dimes are so common today, it seems like it'd be so easy to collect giant jars of coins... but the spending power of the collection back then would be like boxes of 5 and 10 and 20 dollar bills today. It would be tempting to spend those valuable coins instead of keeping them sealed. A couple fistfuls of that coin jar could get you a Filet Mignon dinner at a fancy restaurant!
Menu at a fancy restaurant from the 1960's