This paper examines internet commerce taxation. It concerns who is responsible for collecting sales tax - the seller or the buyer, which depends on nexus between the seller and the state. If there is a nexus, it is the seller’s responsibility; otherwise, it is the buyer’s duty. Nexus further depends on physical presence. However, in today’s e-business, the concept of physical presence has changed. Effective June 1, 2008, New York State enacted the so called “Amazon Tax Law” that an out-of-state online retailer is presumed to have nexus with New York State if it enters into a contract with an affiliate in the state to engage in soliciting businesses in the state by means of web site linkage for an annual gross receipts of more than $10,000. As such, the online retailer is required to collect sales tax from the in-state buyer. The concept of physical presence has been extended from employee or office to web site connection. This paper examines its impact.