Creating a product to sell is decidedly active, not passive. And selling other people’s products is active too when you have to build your own store and maintain inventory. However, if you use dropshipping, all you have to do is set up a store and drive was web traffic to it. Everything else is handled by another company and you walk away with a share of the profits.
The second big takeaway for me, was to pick a niche you know, you find interesting AND where there is demand for your product – ie willingness to buy/pay.  A lot of people only remember the first part of this 2-part formula, and end up creating a blog on knitwear for kittens.  But it’s the overlap of passion and profit that Ferriss stressed so much.