Don't forget walk in take out restaurants. Actually any place folks have to dig into their pockets for something, like money to pay for what they are picking up, or keys while balancing the food they just carried out. Heck even the auto parts store. I've found over $350.00 over the last 5 years, just laying on the ground.
I turn it in, and if nobody claims it, I get it. Funny I've had folks come back looking for phones, keys, credit cards, but no one has ever come back looking for cash.
Dang, I just thought of something. We have a Goodwill drop off on our parking lot. I wonder how much the guy who works there has found?
Folks all the time loose/hide stuff in furniture and books, be willing to bet someone who does some checking could make a decent haul.
And then there's always dumpster diving. Heck the one at our shop has been a gold mine. Goodwill won't take certain things. This year alone, I've gotten a grass blower, and a pair of gas weed eaters. One of them is a 4 stroke, with interchangeable heads. And all of them showed little use. Our shop is in a high rent area, so a lot of goodies show up at Goodwill. I check the dumpster daily for items they toss out.