Personal vs. Business

You can sell one laptop, two laptops, but when you sell 100 laptops per year, i.e. 1 laptop every 3.6 days, that is a business, and that is "working". How about 10 laptops a year, that's debatable.

You can argue until you are blue, but it's like go on a few dates with a few girls, you are fine; but if you are dating 100 girls in one year, you have sort of problem. They are not the same things.

http://www.avvo.com/legal-answers/selling-online-for-a-f-1-visa-holder-975355.html