This also makes gambling of any kind online, even free, illegal in every state. It makes certain types of sales illegal in the whole country as well. It could apply local tax collection laws to companies that don't have such systems implemented. Worse, it could easily cause conflicts, where in one locality, you;re required by law to list certain details on your site, but in another, those details either can't be published, or have to be in a different specific place on your site (contact information for the company, etc). It also opens the door to states passing laws that run afoul of anti-competitive legislation, by passing laws that make it difficult or impossible for non-local companies to sell across state borders online favoring their own local companies. This will all lead to continual court challenges, and waste billions of dollars and tie up court time, and in the end, either Federal Congress will alter the Code of Commerce to correct this, or the supreme court will get involved, undo all this stuff, and then MORE lawsuits will fly.
Here's a simple option, if the judges and congress really think this is a good idea, and don;t stop it, make one minor change: State and local laws enforced outside of the municipality require FULL FUNDING from that local municipality for the continuing education, and money to implement systems to permit compliance, for all non-local entities subject to the law. In other words, if i can't sell something in your community online, I need software to help prevent that sale (since there's no human interaction to prevent it), and the COST of implementing that software should be billed to the municipality, after which an implementation grace period applies, before the seller can be subject to any punishment at all. Should a company sell something into a municipality, and then receive a summons, without having first been notified in advance of the law, and been provided paperwork to begin a funding process, (which a local court in the SELLERS back yard gets to determine what is "reasonable" funding), then any action against the seller is automatically dismissed by the courts, and the locality pays all attorney's fees.
This is a fair and balanced system, where I can enforce my law on you, but I have to PAY for it.