Barkley on 23 August 2016
Well it was a cultural phenomenon, "A cultural phenomenon, also known as the bandwagon effect, occurs when certain individuals behave a certain way merely because other individuals do as well." So yeah the people only playing it because it was popular were going to drop off sooner or later.
The real test for Pokemon Go will be if it survives the winter, I can see it completely dropping off before January.
But this particular drop was always going to happen so it's not really anything to worry about.
