Affiliates manager plugin can be integrated with Easy digital downloads plugin so that affiliate commission is given to the affiliates that send visitors to your store/site.
Step 1 (Install the Integration Plugin)
Download and Install the Easy digital downloads plugin.
Step 2 (Keep the Main Plugins Active)
Simply keep both the Affiliates Manager and the Easy digital downloads plugins active on your WordPress site.
When you receive orders in the Easy digital downloads plugin, the affiliate plugin will award commission to the appropriate affiliate (if the customer was referred by an affiliate).