I think the top grossing chart is a very important metric and I pay attention to it.
TSTO's needle in the chart moves in line with the release of new content/events ( I recall TSTO was back in the top 10 during Easter).
It has fallen as far back as the 50s during a long lapse in content release.
#22 is suggesting that it is still a popular game but there is not an immediate need by its players to buy donuts. It will move back up the charts at the next release.
What is disturbing about the charts trend is that the highs are not as high (2 years ago a constant top 3 app) and the lows are more consistent. This shows the game is running out of gas as it is having trouble bringing in new customers. I think the game has 2 more years (maybe much less) before it has run out of steam and is pulled from rotation. But a 4-5 year run for any game is a fantastic success.
