The User Information web service API has been expanded to allow you to get more information about your opted in users. You can now find out about an individual user and reward them with content, or credits for future purchases for example, if they opt into marketing.
Other great services in the API include:
Is a phone number available?
Give me the phone number
Is an email address available? *NEW*
Give me the email address *NEW*
What currency is a specific user seeing prices in? *NEW*
Is a specific user opted into my marketing? *NEW*
Which users are opted into my marketing?
Is a specific user age verified?
Have a look at the User Information guide for more information.