Key here is voluntary, like pay it or we can nail yah.. So far they are not enforcing it, but it is coming...
How do I know? My uncle Marv's son purchased vending machines from New Jersey. He was kind of cheating on the take and the IRS had enough.
Looking to shut his business down, they busted him for not paying taxes on the purchased interstate sale of the machines.
He gets out of the big house in a few years, he will be fine.
" For instance, some states require that whenever you purchase an item online that is not subject to sales tax, you must report that sale to the state tax agency and pay sales tax on it. However, not every state does this."
Do You Have to Pay Sales Tax on Internet Purchases? - FindLaw