eBay (and Amazon) has been adding sales tax to the price I pay on everything I have shipped to me here in Kentucky for several years. As long as they're not also charging the seller and eBay is actually forwarding the tax onto the state, I don't see what the problem is. If it were practicable, I'm sure the state would want sales tax from every transaction done in the state including yard sales and boy scouts selling popcorn, but some things are too hard/not worth the cost to track and enforce. It used to be that they'd ask you to estimate the amount of money that you'd spent on non-taxed internet/mail order purchases every year at tax time and ask you to pay the state then to make up for what they hadn't gotten on transaction fees. I never felt that I could give an accurate estimate, and most people I knew purposefully underestimated their purchases to lower their tax bill, so I'm fine with them calculating and remitting to the state the exact amount I owe as we go.