[vomjom]

That would never happen.

The problem is that Amazon has no operations in certain states to avoid charging sales tax. Buying Borders would put them in every state.

[InclinedPlane]

Integrating the amazon web store with Borders would put them in every state. Conceivably they could still buy Borders and operate it as a subsidiary without having it affect amazon.com's ability to operate without having to pay sales taxes in every state.