According to a Macrovision report, summarized at Gamasutra, casual gamers are a lot more hardcore than you may think:
37 percent of those who use casual games play nine or more two-hour ‘sessions’ each week.
In addition, the survey, of 789 worldwide participants, found that casual gameplay happens most often at night, as opposed to during commute hours or other ‘quick break’ times during the day, again indicating that the moniker ‘casual’ is a little anachronistic for the gameplay style.
I don’t think this contradicts the conventional wisdom about having a low barrier of entry to a casual game, and making it playable in very small time spans – for the players I think it is all about not having to spend hours getting into a game, and being free to play when and how they want to.
People may still play a puzzle game for hours, but of their own free will …
I think you’re absolutely right. Casual gamers – or entertainment gamers as some in the ISP/carrier business call them – spend quite some time on the games. They can get right to them without spending hours on learning rules and tricks. And they can choose to leave them in an instant. This option to stop the game (and perhaps continuing the same game later) is one of the pivotal reasons for the game’s appeal to this particular type of player.
On a related note, carriers and ISPs have discovered that the casual games are played for extended periods of time, initiated around 7-8 pm. This is ‘counterintuitive’ with regards to the earlier perception that casual games are played during short breaks through the workday.