Have you ever noticed in 90's shareware games how levels that are only included in the paid version are just nearly not as good as the ones in the free version?

Have you ever noticed in 90's shareware games how levels that are only included in the paid version are just nearly not as good as the ones in the free version? That's because you're a much more interesting target before you have made your purchase. A (web) application that has a very useful "free" part with a sign up form at the end (whether it asks for payment or not is irrelevant) will always make me think that "this is very all the cool levels end, from now on it's going to be fairly average and boring".