I want to sell my EA from my website (auto)

Hi There,

I used to sell an EA by hand.

Means, I always had to ask my clients for their account details - registration name and account number - and type this manually into the code.

Then the EA was able to work on their account, and they could not re-distribute my EA.

I would like to automatize this procedure.

I want my clients to be able to pay me (via paypal), and then download the EA [from my website for ex.] which will only work on:

3 of their accounts, that run under their official registration name [same name, 3 different account nr's].

Thanks