أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Customer Services
It's an easy question to answer!
Take facebook as an example; they maintain a huge worldwide database to be sold later without losing any advantage of their database.
The answer is to maintain a database with the maximum information you may get from them, and reuse that database to another customer later on.
