Under throughput analysis, the only factor that matters is the impact of a proposed investment on the ability of a business to increase its total throughput (revenue minus totally variable costs). Under this concept, the main focus is on either enhancing throughput through the bottleneck operation or in reducing operating expenses. This analysis requires a consideration of bottleneck usage by the likely mix of products to be manufactured, and their margins. This is a much more detailed analysis than is contemplated under the more simplistic residual income approach.

The more residual income you can build, the better off you’ll be. In fact, it’s said that the average millionaire has 7 different streams of income. By creating passive income streams that generate money while you sleep, you’ll build wealth faster and diversify the ways you’re able to make money – which helps protect you from the loss of any one individual income stream.

Michael Ellsberg is the author of The Education of Millionaires: It’s Not What You Think, and It’s Not Too Late, which is launching from Penguin/Portfolio in September. It’s a bootstrapper’s guide to investing in your own human capital at any age. Michael sends manifestos, recommendations, tips, and other exclusive content to his private email list, which you can join at www.ellsberg.com. Connect with him on Twitter @MichaelEllsberg and on Facebook.
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.