Sorry I don’t think blogging is passive income. Truly passive income comes in rain or shine – pensions, annuities, dividends, SS. In some cases, even when you are 6 feet under (for your beneficiaries). I would even venture to call it “permanent income” (as long as someone is around to collect). As someone else stated, even rental income is not truly passive since there is a fair amount of work going into keeping renters, maintenance, administrative/financial accounting, etc.
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.