incrediBILL - 6:40 pm on Apr 23, 2013 (gmt 0)
States won't need to police websites because your competitors in compliance will report you to the State, your suppliers, etc. in an effort to shut your site down.
There are services out there, or were if they survived, that have an API that you call and it gives you exact sales tax including State, County and City taxes thus eliminating all the nonsense required and I find their fees a pittance over having to maintain that crud myself. Not to mention the fact that taxes always change and the API provider is tasked with doing it, not me. It's like having a tax pro working for your website.