One big difference is caffeine is a drug and having a chemical dependence is different than impulse. I have nothing to back this up, but I wouldn't be surprised if there's a cognitive dissonance between reasoning about a coffee purchase and reasoning about some other product. Much of the OP's happiness, I'd submit, comes from that caffeine rush. Caffeine (and every other stimulant) makes you feel good and reminds you of feeling good other times you've consumed it. I have fantastic, and specific, memories of having espresso in Paris, Rome, and in my neighborhood. It's just not the same with paying for, and watching, a Netflix video.