AdMob posted some interesting App Store usage data last week, suggesting that the App Store ecosystem is generating $200M in revenues per month prompting at least one commentator to proclaim the App Store ecosystem to be a $2.4B annual opportunity:
If I were to tell you that Apple’s app economy was worth more than $2.5$2.4 billion a year, you would laugh hysterically, shake your head and walk out of the room, yes? Surf on over to some other web site? But here I am telling you exactly that! According to mobile advertising startup AdMob, there are some $200 million worth of applications sold in Apple’s iPhone store every month, or about $2.4 billion a year.
These numbers are significantly higher than our recent estimates, so we decided to look a little deeper. We’re not alone in being a little skeptical, however:
Estimates that the iPhone App Store is worth $2.4 billion a year are utterly ridiculous, iPhone developers say.
“Do the math and that’s a ridiculous claim,” wrote developer Layton Duncan of Polar Bear Farm, an iPhone developer based in New Zealand.
Duncan did the math: $2.4 billion divided by the 65,000 apps in the App Store is $37,000 per app, per year. And while some developers earn that, many do not.
David Barnard of App Cubby, … says AdMob’s number is at least 5x too big. The iPhone App Store is worth $250 and $500 million per year, estimates Barnard….
Here’s what Barnard says are the average prices for Apps in the App Store:
- Top 10 = $1.99
- Top 50 = $2.23
- Top 100 = $3.18
According to Barnard, it takes about 400 sales per day to break into the top 100; and about 10,000 sales per day to hit the very top of the charts. Assume the average sales in the top 100 to be about 1,000 per day. If the average price for an app in the top 100 is $3.18, that’s about $116 million per year for the top 100 apps.
“Most apps sell in the single digits per day, and quite a few don’t sell at all,” Barnard says. “There is a long tail, but it’s a very skinny one. I wouldn’t be surprised at all to learn that the top 100 grosses as much as all other apps combined.”
Comparison between our April 2009 estimates and Admob’s August 2009 numbers:

Admob data is significantly higher than our estimates
AdMob reports:
- a higher number of installed devices
- more than double the number of downloads per user
- a higher percent of users buying paid apps
- a much higher dollar value spent per revenue-generating user
Luckily, there is a rock solid number we can use to adjudicate these differences. Apple has been periodically reporting total App Store downloads and we have been tracking and projecting this number:

April = 179 million, August = 260 million
Total downloads for April were approximately 179 million while total downloads for August were approximately 260 million.
Factoring this back into the AdMob analysis:

Based on AdMob's estimated number of August iPod and iPhone users, the number of downloads per user per month is 5.7, not 13.6
The AdMob data is significantly overstating downloads per user.
So, where is the disconnect coming from? While the total downloads reported from Apple are “hard” numbers, the AdMob data is survey-driven and has two potential sources of inaccuracy. The first source is sample bias:
All data in the feature section is based on survey results taken by users on their mobile device.
Respondents were sourced by responding to mobile ads throughout AdMob’s iPhone and Android networks.
There was no incentive offered to participate in the survey.
There were 1,117 total respondents: 390 Android, 380 iPhone and 347 iPod touch. The survey was run from August 14th-August 21st
Based on the methodology described above, we believe sample bias could explain the entire discrepancy. In essence, AdMob’s sample is skewed heavily toward active users (rather than “all users”). This cleanly explains the higher number of downloads, the higher percentage buying paid apps, and the higher average revenue per user.
The other potential source of inaccuracy is that the survey captures self-reported estimates by users about their usage patterns. Surveys of this nature are notorious for over or underestimating usage as people both lie to give a more favorable impression of themselves (putting forth who they want to be rather than who they are) and just have a hard time accurately remembering what they did over any given period of time.
Taking these together, it looks like AdMob’s results are distorted by a couple of half-truths:
- the people who responded to the survey are unrepresentative of the market as a whole
- they may also be exaggerating a little, or perhaps kidding themselves as well