The idea is good, but the method is winding up the horse from the wrong side ...
When I install Avast, I _ALWAYS_ install it offline from the latest available package directly
from the appropriate place ... and NEVER by any kind of "downloadfromwithintheinstalldownloaderinstaller" ...
So binding the reward to the installation from a certain download site is not the thing ... it should be bound to the eMail-licensing. But it would be too easy to just add a "reward eMail field" to the filling-out-fields inside the registration page.
The way should be that the Installer (that person that should get the reward) would have to add the eMail-address of the User to it's "reward list" (a list kept online at avast inside the account of the installer person); and the installer only then gets the reward, when the eMail-address of the User is not only requested for a license, but also that license number was activated in an installation of avast. The reward is given only if all the three things are done:
1. the eMail address of the User is inserted in the list of the Installer account (that is done by the Installer person onto his list inside his account)
2. the user requests a license with that email address
3. that license is used to activate an installation
(point 2 and 3 usually (but not always) are done within one step)
All these three things have to happen within one week - regardless of the order of each (often it is the case that I install somewhere avast direcly at the place of the user from my stick, but he does not have a thick internet access, and I don't know his eMail-address in advance.
So if all these three things happen within one week, the reward is given; otherwise it is void.
That would be the real solution!
Btw: adding some check information (that is displayed at the installation and that the installer person would have to add to the eMail-address) could also be considered, but should not be necessary as it's the activation that counts.