Have you ever noticed someone that looked like sort of a dirt bag, or an unscrupulous character eyeing your tip jar? It happens all the time, in fact several months ago, I was sitting out in front of a Starbucks on the patio, and someone came in and stop the money out of the tip bowl, however, someone saw them, told the manager, and The manager called the police. The culprit and thief thought they got away, and they were loitering around the shopping center, luckily the police came right away and the person was arrested.
This did not need to happen, and there are ways to prevent it from happening. That tip jar should be located in a place where people have to reach to put in the money. It also will help you get more money, because whoever is putting money in the tip jar has to be quite clear about doing it, and they know that you will notice, and therefore they are likely to put in more, which is a benefit to Putting the tip bowl just out of reach.
It also means that for someone to steal the tipage jar they have to reach over quite a ways to put their grubby little hands inside to grab the money, quickly bringing their hands back, and stuff the loot into their clothes. As they are eyeing the tip jar, they realize it may be more difficult than they think, therefore they do not try. In this way you are keeping the somewhat dishonest person honest, at least in your store during that visit.
Now there are people who will just flat out rob you, and use a distraction to steal your tip jar, and there are those who will rob you for everything in your cash register too. The more difficult you make it for them, the safer your money will be. I've talked to some store owners who have stopped putting a tip bowl out because it has been robbed so many times, but is that really fair to the employees who are going to split those tips?
Okay so, philosophically you could argue against having a tip bowl at all, and reason sometimes that you expect your employees to give great customer service without being bribed by a tip. But also please consider that some customers, like myself, enjoy giving tips for exemplary service. It makes us feel good, which would be the other side of that debate. Whatever, whatever you do, if you choose to have a tip jar consider a strategy to keep that money from disappearing. Indeed I hope you will please consider this.