I have gone through the Android documentation and other blogs related to using the Places API in an Android application. Everywhere it suggests to use the API_KEY to call the REST service. The API_KEY being the same throughout the project/application. There is a limitation of 1000 requests per day.
Now if my application is installed by many users, then the request limit will be easily exhausted if the same key is used by everyone.
There would be some way to generate the API_KEY for individual user. But how can I take care of it in my code?
You can have the quota raised to 100,000 requests a day if you verify your identity:
Users who have verified their identity through the APIs console are allowed 100 000 requests per 24 hour period. A credit card is required for verification, by enabling billing in the console. We ask for your credit card purely to validate your identity. Your card will not be charged for use of the Places API.
You'll find this information and more if you go to the Google APIs Console, select Services and click on the Pricing link on the Places API line.
100,000 requests a day is a lot and should be sufficient unless your app is extremely popular. And I don't think that creating several user to generate several API keys will be possible without violating Google's terms and policies.
来源：https://stackoverflow.com/questions/12786465/google-places-api-in-android-api-key-for-individual-users