Comment The Royalty Tax Definition Thru 2010 (Score 2) 5
And, actually - according to the law through 2010... the tax on royalties applied to worldwide revenue...
RCW 82.04.2907 - Tax on royalties from granting intangible rights
(1) Upon every person engaging within this state in the business of receiving income from royalties or charges in the nature of royalties for the granting of intangible rights, such as copyrights, licenses, patents, or franchise fees, the amount of tax with respect to such business shall be equal to the gross income from royalties or charges in the nature of royalties from the business multiplied by the rate of 0.484 percent.
Microsoft got around it by claiming to record the sales in Reno, Nevada, not in Washington State.