Semantics, and perhaps pedantic, but I'd like to point out the following as there is a lot of misunderstanding.
When you buy something for yourself or your business, you PAY sales tax. There are exemptions to this, your accountant can help.
With coin drop you are COLLECTING sales tax from your customers on the state's behalf. At a later time (annual, quarterly, monthly depending on your state) you make a sales tax payment to the state for what you collected from your customers on the state's behalf.