For me january has always been the worst month. Last year the drop in january was about one third of december earning.
This year it looks like january earning will be half of december.
How was your monthly earning compare to january last year?
How much percentage drop?
Monthly Earnings have grown not dropped.
Sorry to say it this way but this question is worthless any good developer would be making new apps not just sitting around on old apps.
Yes if a developer did nothing then you would be able to compare two January's earnings but what developer in there right mind would do nothing in one year ?
For me january has always been the worst month. Last year the drop in january was about one third of december earning.
This year it looks like january earning will be half of december.
Strange, January for me has always been better than December. Just two years, but last year was better and this year is on track to be significantly better.
A few days before Christmas to New Year's is the best week, but early December has never been great. Consistant daily January sales mean more $ in January than in December.
Also, I agree with other posters that year to year things should change quite a bit if you are releasing new apps, and learning from your mistakes and from the app store ecosystem itself. There are more devices, not less, every day. Also new developers, but new developers don't have the experience to know what works yet, so a seasoned developer should be able to leverage device growth better than a new developer.