Good lessons: * Make pricing easy to understand * Don't make customers guess how many widgets they'll need * Don't make customers afraid they'll run out of w

Good lessons: * Make pricing easy to understand * Don't make customers guess how many widgets they'll need * Don't make customers afraid they'll run out of widgets or need to pay a different amount later * Convince customers that tier X has everything they'll need and is cheap and easy In other words, make the checkout funnel as smooth and frictionless as possible.