IMHO this (disallowing trials) is a big mistake. I very rarely would buy an app that I can't try. Of course I can afford to lose $1 or whatever - it's not the cost but the fact that I had been scammed what would infuriate me. It would only make sense for the app makers to turn my loss aversion against me - if I already used the app for a couple of days and liked it, now the choice for me would be "lose it or pay measly $2" - and that would be completely different game. Given that Apple exercises total and absolute control over the whole ecosystem, it could easily make trial system that makes apps free for 3 days (or 15 days if the developer chooses) and then makes them stop working until you pay. I think it would make Apple ecosystem much more friendly to the user, because frankly reviews are usually worthless and screenshots etc. are not much help either.