The Illinois Supreme Court ruled 6-1  that the US Constitution,

which makes federal laws supreme over state law, and 

federal “Internet Tax Freedom Act”, 47 U.S.C. § 15 ff.,

prohibit new state Retailers Occupation Tax and Service

Use tax sections (35 ILCS 105/2(1.1) and 35 ILCS 110/2(1.1).

These changed the definition of what it meant to have a

taxable physical presence in Illinois to include “affiliate

marketers”, or “performance marketers”, who get paid

to refer traffic to otherwise out of state sellers. Discrimination

against electronic commerce was disallowed, since catalog and

print ads and other conventional marketing with performance

based results would not result in taxability under the Illinois

statute. The case name is Performance Marketing Association,

Inc. v. Hamer,  2013 IL 114496, Oct. 18, 2013,

http://www.state.il.us/court/opinions/SupremeCourt/2013/114496.pdf

Practice Tip: States like Oregon do not have sales taxes, so 

customer shipments from warehouses there may have a price advantage

over those in states, counties, and cities that impose high sales taxes. 

Email me at wprice@growthlaw.com if you need more information.