With so many governments struggling to make ends meet, more states are looking at how to collect more sales tax revenue from online purchases. While Internet users may not like this, it seems like this is primarily being held up by complications about how to collect the money:

Under a 1992 Supreme Court ruling, businesses are responsible for collecting sales taxes on every sale they make in a state where they have a “physical nexus.” In other words, if the business has a store, an office or even a single sales rep in your state, it’s supposed to tack the state’s sales tax onto your bill.

Online retailers like Amazon.com typically don’t add the tax, except in the states where they’re based or where they have physical facilities like warehouses or distribution centers. Amazon, for example, collects sales taxes only in Washington (its home state), Kansas, Kentucky, North Dakota and New York.

The tax is still supposed to be paid, however. And if the seller’s not responsible, then you, the buyer, are. In general, you’re supposed to voluntarily file your own report and pay the standard tax on your out-of-state online purchases. (The appropriate forms are available on state tax agency websites, revenue officials are happy to remind you.)

But it turns out that the vast majority of Americans are completely unaware of those rules, so the forms don’t get filed and the taxes don’t get paid — to the tune of $8.6 billion in 2010 alone, the National Conference of State Legislatures estimates.

Two quick thoughts:

1. Why have states waited so long to get on this? Perhaps they didn’t want to look like the bad guys while things were relatively good.

2. If more of these taxes are paid, what effects would this have on Internet commerce? There would still be benefits to Internet purchases: no need to go out to a store, often a lot more options, delivery to your doorstep. At the same time, would this help traditional retailers?