Many people still think the iPhone app market is a chaotic melee where hits are created and then vanish in an unpredictable way. In some ways, the opposite is true: the iPhone paid download chart is extraordinarily conservative, effectively frozen in time. The entertainment industry tends to be dominated by fresh product. On December 28th, seven out of the top-10 movies in America were released within 10 days. The oldest was released 50 days earlier. Seven out of the top-10 songs on the Billboard 100 were released within the past 91 days. The NPD Group’s chart of the top-10 console games in November was ruled by brand new titles. But the mobile app market is the mesmerizing exception.

Year after year, people expect old school apps to start fading as a new generation steps up. Yet the ancient hits from 2009 and 2010 still hold tight while new entries race up the chart and drop out like clouds of mayflies.

On December 28th, six apps on the iPhone’s top-10 paid download chart were at least 400 days old. Three apps were 800 days old or even older. Since Angry Birds Star Wars and Bad Piggies are spin-offs of the 1000-day-old Angry Birds saga, fully eight out of the top-10 download franchises belong to the Methuselah Club.

Only two of the top-10 iPhone apps are fresh, Wipeout and Need for Speed, both boosted by massive name recognition from other media platforms. What this means is that the only original mobile app success stories on iPhone on December 28th, 2012 were games launched between 2009 and 2011.

This is truly exceptional. We have never seen a content industry where hits from previous years are trumping over new entries to this degree.

There are eight apps in the iPhone’s top-40 paid downloads chart that are 900 days or older. These blockbuster games were mostly created back in 2009 and they populated the evolutionary niches of the iPhone app market with ruthless efficiency. The first wave of quality apps that arrived in 2008 were a bit too crude to become evergreen. The Class of 2009 was just sleek and deep enough to render future challengers impotent.

The 1,119-day-old Words With Friends is the word game that’s good enough to see off new challengers year after year. The 1,043-day-old Angry Birds and its brood of spin-offs are the iconic catapult games. The 1,249-day-old Doodle Jump is the platform jumper that won’t fade away. The 1,044-day-old Plants vs. Zombies is the defense game champion.

These old-timers have effectively conquered most of the popular casual gaming niches. They are proving to be exceptionally difficult to displace, mostly because in the app market, the product evolves. Unlike blockbuster movies or Billboard hit singles, the top apps keep getting new expansions and upgrades, often every two or three months.

New consumers now compare Angry Birds with its literally hundreds of levels to other catapult games with far lower level count. Of course Angry Birds is better value for your 99 cents. The massive network of users that Words with Friends has amassed is fiendishly difficult to replicate. Plants Vs. Zombies has expanded to a sprawling saga with an endless series of bonus levels and extras.

In the free download category, there is a cornucopia of innovation and brand new challengers vying for top-10 positions, both on iPhone and iPad platforms. But the paid app market remains dominated by the old champions, perhaps for years to come. Maybe that is why most vendors developing new games now only target the free download segment.