It's all about net present value and nothing to do with eyeballs. A startup with no revenue can only have a spectacular valuation if investors believe the time

It's all about net present value and nothing to do with eyeballs. A startup with no revenue can only have a spectacular valuation if investors believe the time and risk adjusted future profitability of the company merits that valuation. The alternative explanations (the investors are relying on the greater fool theory, or are themselves fools), seem pretty unlikely.