This question seems to have been beat up on this site, but I can't find a direct answer.
If I have an internet business incorporated in Delaware that sells software online, and I personally live in North Carolina, yet my developers/designers/etc span from Virginia to Ukraine - what state am I 'doing business in' from a taxation standpoint? I assume most people will say "North Carolina', but why does it matter where I personally live? Is it the official business address I put down on my IRS forms that determines where the corporation is? If so, what's stopping me from opening a UPS box in Nevada (which has no income tax)?
Perhaps I'm an idiot, but I am unable to make a connection here.