Amazon finally agreed to pay tax in California 6 months before they rolled out Amazon 1-day. In Washington it was three months. Most analysts, in fact, saw Amazon's sales tax agreements to be predictors of where they were rolling out 1-day next The law as it exists basically says "if you've got an employee there the state can make you collect sales tax" but the law as it exists requires states attorneys general to devote resources to pursuing out-of-state companies and it doesn't pencil out. Amazon knew that building fulfillment centers would give CA and WA the ammunition they needed to make it worthwhile so they capitulated. The fact that they're now paying it everywhere is an admission that they see things going that way and it was worth capitulating for first-responder advantage.