I wonder who will collect the tax, the retailer when the sale is made or the tax payer when filling out their tax return?
The first. Many states already require the latter—saying if you purchased and didn’t pay taxes, then you are required to declare and later do so. Even as the article notes, most people never did. I sure didn’t when living in states where this was noted on the tax return.
I used to purchase cigarettes online for personal use. One day I got a letter from the State saying they knew I was buying cigs and they wanted me to pay taxes on past purchases. The good news is that it was a small amount of money, so I just paid it. The bad news is that there was no longer any incentive for me to buy online, so I stopped. There is not much that works better than taxes to depress consumer enthusiasm.
I'd prefer to see the taxpayer have to pay the tax directly to the taxing agency, whether it's the state or local government. When the tax is included in the price (or taken out of a paycheck) the taxpayer often doesn't understand the full extent of the taxation.
If people had to write the check for every cent of tax they paid, maybe they would give more attention to how that money was spent.
Tax is usually levied at point of sale.