I don't claim to be especially economically savvy, but isn't the fundamental premise that there's a bounded conversion between revenue and profit? Iow, that one can trade a decrease in revenue for an increase in profit by certain business decisions.

If so, then it's natural that stock price increases when revenue increases, albeit at a discount to actual profit depending on what your expected revenue:profit conversion ratio is.

The interesting part is the next step. Someone buys a stock expecting to benefit from the exchange (sell at a higher price that one purchased it for). Thus, if the stock price is correlated with revenue, and Amazon can increase revenue even without increasing profit, stockholders will still be happy.* Stockholders are looking for increased value for their stock, not any particular metric thereof.

*This is assuming Amazon finances the revenue increases through free cash flow (as mentioned elsewhere) rather than diluting stock