Queries per Second (QPS) is the number of times a request is sent to a server per second. Accordingly it is a measure of how much traffic a particular query server is receiving in one second.
QPS is a measure that is also relevant in terms of mobile and digital advertising. It is an indicator of media capacity for ad networks and ad exchanges because it provides information about the power and reach of these networks.
The more queries per second (Ad Calls), the more popular a search engine or advertising platform will probably be for digital marketers.