I think you should use Financial Samurai to raise your passive income. You’ve already proven that you writing 3 articles a week is enough to not only sustain the site but grow it. Why not have more guest writers post articles? Since you started with the extra post each week I’m guessing traffic is above your normal growth rate. Leverage that up with more posts and my bet traffic will continue to grow.
In equity valuation, residual income represents an economic earnings stream and valuation method for estimating the intrinsic value of a company's common stock. The residual income valuation model values a company as the sum of book value and the present value of expected future residual income. Residual income attempts to measure economic profit, which is the profit remaining after the deduction of opportunity costs for all sources of capital.