Even those who think "I'd decide if I want to buy the game in less than 4 hours" are also likely to think "it's only 2 bucks more to have it for a week" and try

Even those who think "I'd decide if I want to buy the game in less than 4 hours" are also likely to think "it's only 2 bucks more to have it for a week" and try to use that as a hedge against the likely scenario of wanting to play a little bit more, but not liking the game enough to buy. It's very rare to find someone who would pick the 4 hour decision as a result of rational process (minimize total outlay to find your favorite game of a group, and buy only the best.) Sure, a few people will take the 4 hour option, but I'd bet their internal numbers show that the presence of the 4 hour option drives a lot of 1-week options -- and they'd rather rent 4 games for a week each ($28 revenue) than one game for a month ($14 revenue).