How does sales tax work for online shopping malls?

Question

I'm not quite sure how the whole sales tax works for businesses when starting a online shopping mall...

can someone please fill me in?

Answer 1

If they have a store located in your state of residence, then they collect sales tax, no store no sales tax/

Answer 2

At the present time, if you have a physical location within a state you are required to collect sales tax for sales within that state.  

New York State recently (June 01) became the first state to impose requirements of taxation on sales to NY residents.  Expect more to follow.