YouTube brought in nearly $4 billion in estimated ad revenue in 2018. So you can earn a potentially large income by uploading videos to the platform and then watching those ad dollars roll in. You may need or want to upload videos regularly, which isn’t especially passive. But you don’t need to provide a specific product or service directly to customers.
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.