Downloads

Total downloads is the mainstay of your rank; the more you have the better you’ll weather storms. But “download spikes” — clusters of many downloads in a short timeframe, for example as the result some PR you’ve been doing can boost you up the ranks fast for short periods of time.

Revenue

Having only really worked on free apps, I’m guessing that revenue plays a role at least in ranking in the top paid apps discovery lists. It would make sense that Apple and Google give greater visibility to apps with a track record for generating cash to gain.

App Starts

Just getting downloads isn’t enough; app starts demonstrate that people actually use your app and act as a measure of engagement and retention. Apple is believed to have introduced this some time in the summer of 2013.

Number and Value of Reviews

Again this showed up on the App Store in the summer of 2013. Kinda obvious — if people rate your app well, it helps your rank.

Keyword Relevance

How well your keywords match with what people are searching for. To an extent this is more about discovery than ranking but if you pick popular keywords, you’ll have more competition and struggle to rank well. Use the store search autocomplete to help you identify popular keyword combinations that others might have missed.

There are ways you can get round that pesky 100 character limit by listing in multiple territories but it’s likely a violation of the intent of the guidelines even if it’s not strictly breaking any rules so will pass on the details.

Recently Updated

On the App Store, your existing user base updating your app will give you a short term uplift. As the saying goes, release early, release often.

Actually, on the App Store, releasing early is probably a bad idea — never sacrifice quality for the sake of meeting arbitrary deadlines. But that’s another story...

Retention / Uninstalls

This one I haven’t entirely convinced myself of first hand but have seen quite a few claims that Google uses uninstalls to rank apps down. A good read on this here.

Country

For the App Store, downloads, reviews, usage etc. in one particular store region e.g. Spain have the greatest value in that territory. There does seem to be some global overlap though. For example when Yo! was getting a ton of downloads in the US, it climbed pretty fast on the Swiss app store before anyone really knew about it here.

Word is this is less true of the Play Store; that territory only plays a small part in rank. Cannot confirm either way.

Social Proof and Backlinks

Google purportedly tracks things like Google+ +1’s, Twitter and Facebook referrals as ranking influencers as well as backlinks in general. Would make sense — they have years of experience doing so from the web.

Apple is believed not to, although a few clicks in their recently launched App Analytics is enough to tell you they’re well aware of traffic sources and would be capable of doing so…

Further Reading

Some related reads…