Developer Finds It Takes Just Under 4K Downloads To Break Top 10 Paid iOS Apps, Over 7K To Rank Fifth And Up

The App Store is somewhat shrouded in mystery, thanks a secret recipe that Apple uses to determine what apps shoot up the charts. Downloads play a big, influential role, but they aren’t the only factor. That being said, Readdle, developer of Calendars 5, Scanner Pro and many other apps, shared some data with us today that could help other devs get an indication of what download numbers might lead to top ranking.

Readdle’s Denys Zhadanov says that the company has found it takes between 3,500 and 3,800 downloads per day of a 4.5 star ranked app to break into the Top 10 U.S. Paid iPhone app list on Apple’s mobile software marketplace. That’s based on their experience with Scanner Pro, a universal app which recently cracked the top 10, and Calendars 5, their revamped calendar application recently released for iPhone.

This echoes a study released by app research firm Distimo back in June, which found that a paid app needs over 4,000 downloads per day to reach the top 10 spot for Apple’s paid iPhone list. Apple has been known to change its App Store ranking algorithms, so that could be what’s behind the small discrepancy between Readdle’s experience and Distimo’s findings, but it’s also well worth noting that Zhadanov believes things like ratings and feedback might also affect the threshold at which an app breaks into the top 10.

Based on what they’ve seen with their apps, Readdle can make some educated guesses about what factors affect App Store ranking: In addition to ratings, they say there’s an “inertia” factor at play, which means that some stickiness applies to rankings, so that a dramatic increase or decrease in app downloads for one particular day won’t necessarily move you up or down in the rankings once you’re in the top 10. There also seems to be a bonus for brand new apps, which is eventually counteracted by the so-called “inertia” effect.

“That’s why it’s important to reach the highest rank possible during the first few days,” Zhadanov says. “Because it’ll be harder [to climb] later.”

Some other observations from Readdle suggest that reaching higher spots in the chart requires two times or more the number of downloads it takes to break into the top 10. Around 7,000 downloads per day should result in a #4 spot for an iPhone app, or a #2 spot for an iPad app, based on their experience with a Universal (works on both) software release.

iOS 7 is generating a lot of renewed interest in apps and the App Store from consumers and developers, so it’s interesting to see with this snapshot that the download threshold seems not to have gone up considerably from back in June. It is perhaps a sign that Apple’s ranking algorithm has been tweaked to consider other factors more strongly in its ranking recipe mix.