CTIT, stands for Click to Install Time, is a type of measurement used to detect anomalies in time from when a user clicks on an ad to the install. It helps mobile advertisers to detect attribution fraud types like click spamming and click injection. 

A short Click to Install Time means there is an abnormally short time between a click and an install and this gives an idea to mobile advertisers about if there is a fraud attempt on attribution of installs.

CTIT analysis can be conducted via attribution tools (Mobile Measurement Partners) or third party mobile ad fraud detection and prevention tools.