I was thinking that depending on the time period made, maybe it was for pennies. Think about it for a minute, back then a penny got a kid a lot of candy, unlike today. Plus unlike today, kids were excited over getting pennies. Heck when I was getting my quarter allowance in the 70's I was excited that I could get a new comic book.
it is a registering dime bank from the late 1920's to very early 1930's. usually a bank give-away item to promote savings, it probably once had a metal plate with the bank's name and address on it. most of these would stay locked until it registered 5 or 10 dollars and then it would unlock
just a side note..... I've collected antique still banks for some years, and have found in a lot of cases that the manufacture date is often a good many years after the patent date. I have one example that wasn't released for public sale for almost 25 years after the patent date. This particular bank I'm uncertain of, but still feel strongly that it wasn't released until the 20's. But I'm no expert. I just like them and think they are cool and very well made. I collect them because they remind me of a time when most average commerce was with coins.