According to a report from app testing firm Swrve, mobile free-to-play games tend to have dismal retention rates. In addition, many mobile game players rarely spend any money in these apps. Sixty-six percent of users stopped playing a new game after one day and 19 percent stopped playing after only opening the game app once. Swrve also found that players spent an average of 45 cents over 90 days, and 53 percent of the spending in games happened within the first week of playing.

The amount of players who spend any money in mobile games in the first place is very low, according to Re/code. Swvre’s monetization report from February showed that only 1.5 percent of players spent money, and the top ten percent of those spenders generated 50.8 percent of the game’s total revenue.

Swrve CEO Hugh Reynolds believes companies should be cautious about user acquisition so that they are not losing out because of fickle users. One suggestion to increase user retention is to consider adding tweaks to the tutorial section of mobile games. This might help players struggling with a certain part. However, players who power through the first stages probably would not respond to this type of adjustment.

“The problem is that not all players would respond the same way to the same signals,” Reynolds told Re/code in a related article.

On a happier note, mobile gaming is the strongest category in app stores across the board. In Google Play and the Apple App Store, 41 percent of downloads were gaming apps. On the Amazon Appstore, that number was 61 percent, according to The Wall Street Journal.