Amazon has started collecting taxes in every state in which there is a sales tax. That’s a departure from the past, when the online retailer balked at collecting sales taxes, including in Arizona.

But the company has been expanding its physical presence in states, which has bolstered arguments that it should pay sales taxes, just like brick-and-mortar retailers.

This is something Amitabh Sinha studies.  He is an associate professor of Technology and Operations at the Ross School of Business at the University of Michigan.

How much of Amazon starting to collect these taxes has to do with the fact that it’s increasing its physical presence in states in order to provide some of the services it’s now trying to provide?