> A simple way to solve the problem is to levy an internet sales tax, which is the same percentage as the corporation tax that these companies should have paid if they were operating solely in that country in the first place.

Ah, but how does something like Google work, then? They don't sell a product to people all over the world (where tax can be collected); people all over the world are the product, and they sell that product to advertisers mostly from the US. Google uses the population of a country to make money without actually receiving any money from anyone in that country.