How To Estimate App Sales from iTunes Ranking
Oz Weather has now been selling for long enough, and over a large enough range of iTunes app store rankings to enable me to get a good handle on what level of sales you need to achieve a particular ranking – or conversely, what ranking you would achieve from a given level of sales.
Points to Note
- This analysis is specific to the Australian iTunes app store – US and other stores will likely have much higher sales levels for similar rankings, as a consequence of having a much larger iPhone ownership base.
- The rankings are for Paid Apps only – Free apps are likely to have much higher download levels for similar rankings.
- The rankings are overall app store rankings ie. across all app categories. Rankings within individual categories would obviously have smaller sales figure, although given the dominance of games in overall rankings, these results probably would also apply quite well to the games category on its own.
- This analysis relates to sales over a 7 week period from 1st Nov 2008 to 19th Dec 2008 – The nature of the relationship may well vary with time as i) the total number of iPhone owners keeps rising, and ii) the total number of apps available in the app store keeps rising.
- The curve is a best fit to the actual data points using a logarithmic formula.
Some Key Conclusions
- To get top ranking in the Australian app store, you need to make more than 300 sales per day
- To get into the top 10, you need to make more than 100 sales per day
- To get into the top 20, you need to make more than 50 sales per day
Applying the Findings
So now you can get a good a pretty good estimate of how much money your favourite (paid) apps are making in the Australian app store. The following example is for “Pull My Finger“, which is currently ranked 5th in the Australian app store. (BTW I’m not saying this is actually my favourite. Its not! This is just for illustration.)
- Get the overall rank of the app ie. 5th
- Find the corresponding daily sales from the graph ie. about 200
- Multiply by the app’s price ie. 200 x AUD$1.19 = AUD$238 per day
- Deduct 1/11 for Australian Goods and Services Tax = AUD$216 per day
- Deduct 30% Apple’s share = AUD$150 (US$100) per day
Of course this app is selling worldwide, and this is just the Australian component of sales. I’m not sure of its rankings in the US or elsewhere, but one can probably reasonably assume that it might be selling, say, 20 30 times more worldwide than it sells in Australia alone. So taking this one step further, one arrives at a rough estimate of AUD$4500 (US$3000) per day worldwide.
Daniel Bradby (see comments) has provided an excellent link showing a similar graph for worldwide app sales – although supported by much sparser data. It appears to show that worldwide app sales are around 30 times more than those in Australia, rather than my initial estimate of 20 times. I have updated this article accordingly.
NB – There is now a more recent article with updated data and more detailed estimates of world-wide sales/rankings ratios.