I've only read part of the book, but I think what Tim is getting at is more along the lines of running a business where that generates income without you having to be present all the time for it to keep operating. He talked about his vitamin/supplement business that is run with mostly outsourced labor, from production to sales.

So, if you've contracted with someone to make a product, someone else to run the website to sell it, and someone to handle the logistics of shipping and payment processing, there will be times when you're theoretically making money without "working."