The current sales tax 'nexus' law varies per state and many states currently don't have a law in place, but probably will soon to get in on the sales tax bonanza.
Using Jersey Jack as an example:
*If JJP was doing more than $10,000 in volume and/or have more than 200 transactions annually in Washington State then they would have to charge customers in WA. sales tax.
*Ohio rules or 'nexus' currently is $500,000 or more in sales so JJP probably would not have to charge sales tax there.
*Alabama, Ct. and Ms is $250,000 to hit the sales tax
*IL, Ky, RI, top out at $100,000 or 200 transactions
Point is, state internet laws are currently all over the place with Pa, Wa, and Ok being the lowest at $10,000 billed annually before sales tax would be charged.
Stay tuned, as if Congress takes a run at this (T.B.D) it will all change, as right now it's up to each individual state to decide.