Who has a large number of second

I am looking for cooperation with who have a large number of second-hand mobile phones.

Now i am going to tell the details:

I am a technicist of testing App on mobile phones. This is a dating App and i need mobile phones located in these developed countries to download and register as much as possible. So if you are selling second-hand phone or you have several phones in your hand, please contact me. The commission is 3 dollars each registration.