There are several factors that govern how many apps installs might qualilfy for a location-based push notification:

• The total number of app downloads and the proportion of these active over the relevant period (e.g. a day)
• The opt-in rate for push notifications
• The opt-in rate for location services
• The audience filter rules and send time for a specific message
• The size and location of the region(s) used in the targeting  

If there is an unexpectedly wide varation between anticipated message send volume and actual message send volume, then start troubleshooting by carefully checking how the message was set up, including which region(s) are being used. The explanation might be a misconfiguration in the message targeting.

Even if the targeting looks correct, by definition the more complex the rules for a message, the more targeted and the smaller the audience for that message. (Conversely to maximise a push notification message's reach, 'send to all' using your app vendor's push messaging interface). 

To troubleshoot:

• Check the total number of app downloads and activae app users for the relevant period (e.g. a day). 
• Check the audience filter rules. Perhaps these are