Last year, in the spirit of simplicity, New York's Legislature exempted large marshmallows, a benefit long ago extended to mini-marshmallows. Even taxpayers are a complex subject. Many consumers, such as schools, churches and nonprofits, are exempt from paying sales tax. Thirteen states exempt all those groups. Hawaii and Louisiana don't exempt any of them.
Most states fall somewhere in between.
The system wasn't always this convoluted. The sales tax grew out of the Depression, when governments were strapped for cash. Mississippi was the first state to tax retail sales, in 1930. The last state to institute a sales tax was Vermont in 1969. Since then, state and local governments have raised and lowered rates, taxed new products and services and exempted others.