Extremely inconsistent revenue/ecpm with AdMob

I’m running AdMob on my 3 apps and since I released them 3-5 weeks ago I have been having very inconsistent revenue. One day I can have $0.17 eCPM and a couple of days later I can have $1.50 eCPM with the exact same CTR. Take a look at the screenshots below and you’ll understand. Can someone please explain why I’m seeing such a ridiculous difference in revenue from day to day even with roughly the same number of impressions and CTR?


There is great variation in the day to day revenue from each of the ad networks.

One can attribute it to various campaigns by advertisers (for AppWalls for instance, there have been days where I have seen the same apps on a Leadbolt AppWall as well as an AppBrain or another AppWall).

Then the campaign abruptly stops.

A second reason could be statistical variability because of low sample size.

Now the number of impressions can be 10K in a day - but the clicks or installs (for AppWalls) are in the 10s i.e. 80 or 20 etc. - this figure is still pretty small - and can see variations.

The click-through-rate also depends on the types of ads running that day - some ads may attract users more than others.

Then we have the “what advertiser will pay” i.e. with admob for instance there is no bar on what type of ad will be shown (low paying or high paying) - though with Admob eCPM floor beta you can specify an eCPM - however this is just approximate but generally works - but the fill rate will then go down to 10% or 20%. With AppWalls even you can get huge variation in what advertiser is paying - on some days it seems someone is running a campaign and they are willing to pay much more or something.

So all these factors can contribute.

I suspect with DAU maybe like 50K or something maybe you start to see some stability in the numbers (?) - however the variability of advertisers, advertiser quality etc. will remain even then.

It is also possible that the ad networks lump revenue from one day into the other - for example Admob says their Adsense-derived revenue (?) is delayed 48 hours or someething like that (?). If there is some element of delay there ther could be lumping going on - i.e. some days they lump it to the next day (leading to low today and much higher revenue next day) … so it could be that type of stuff maybe.

Thanks a alot for a really good answer!

3 months ago I had those numbers like you, including the varying revenue. Just wait until you get 50k+

So you are saying with 5x more impression volume, the numbers start to stabilize day to day - or get worse ?

I guess the revenue gets worse but the amplitude reduces.