Odd Rankings Fluctuations Continue in Apple App Store

Today’s Top RankingsYesterday’s Top Rankings
Newer titles dominateOlder titles resurface

Apps that got a bump on the free charts over the past week — possibly because of a change in Apple’s ranking algorithm — look like they are declining today.

Several pay-per-install networks, which developers use to break into the top of the charts, told us they were finding that rankings had shifted in an unusual way through the end of last week. Flurry, which has an analytics product in 80,000 mobile applications, said it suspected Apple was starting to factor in more than download rates. Now it looks like Apple may be reverting changes and starting to allow new apps to bubble up again.

If you compare yesterday’s top free rankings to today’s, you’ll see that older apps like Facebook, The Impossible Test (which originally came out in August 2009) and Zynga’s two-year-old title Words With Friends dominated the charts yesterday. Today, all of the top-ranked apps are relatively new. Microsoft’s Photosynth and Crackle came out yesterday while Stupidness 2 came out on April 14. Stylish Sprint originally came out in January but had an update yesterday.

The suspected changes during the last week produced some odd jumps in the rankings. Facebook, for example, rose to the #1 position in the U.S. on Thursday and held it through the weekend even though the company made no changes to its app during that time. That’s a position it hasn’t held since at least July 2009 on the U.S. charts, which is as far as the historical data on app tracker AppAnnie goes back.

Ranking Fluctuations in the Past Week

Other apps also inexplicably rose even though they made no updates or promotions. We made the chart above, compiling data from AppAnnie, Applyzer and the app store today to show the peak and decline of several applications. We also noted when they last updated their apps, to show that these companies aren’t necessarily doing anything to boost their titles. Most are well-known, consumer Internet brands like Pandora, Skype and Netflix that presumably attract high numbers of daily active users.

Apple hasn’t returned several requests for comment so we can’t confirm whether the company has changed app store algorithm.

Distimo, a cross-platform app store monitoring tool, also ran some tests on its data this morning and couldn’t definitively prove either way whether a change had taken place. If one did, the company said only a small subset of applications saw significant changes. Their assessment conflicts with what the large pay-per-install networks like Flurry and W3i, who push developers into the top of the charts every day, have told us.

One this is clear though. Even if Apple is dialing down some of the levers it may have changed last week, the company is moving to exert more control over the ecosystem. Several developers that use offer walls to earn extra revenue have said their updates were rejected by Apple. It appears that the company is looking to clamp down on the practice of pay-per-install, where developers pay for downloads to break into the top of the charts.