How does an application of a particular website retrieve data of old users of websites?

[AC Question]

How does application of a particular website retrieves data of old users of websites?

I am creating a app for shopping website , i want to get details of those users who signed up on website before the app was launched, how to retrieve that data?

 

[belodion]

Re: How does application of a particular website retrieves data of old users of websites?

You would have to ask the owners of the shopping website.