So, just what happens to an Android game after you post an update to Google Play?
There have been two significant versions of my Ludum Dare 23 game to exist. Version 1 was what I submitted to the contest, and was available on Google for approximately 21 days. When I released Version 7, Version 1 had approximately 50 installs at the time. As you can see, the upgrade caused an immediate drop in version 1 installations, and as you can see the rate of Version 1 installation has dropped over time as people upgrade to version 7.
But look at how many people still are on Version 1. It accounts for just over 24% of the install base. 20 people have not chosen to upgrade, for one reason or another, even after almost three weeks.