Aha, I misunderstood what you meant by "masked URL"; I thought you were inquiring about link-shortener services like TinyURL. The landing page URL does not matter for affiliate referrals, as long as the buyer was referred to your page through an E-junkie affiliate link and uses E-junkie purchase buttons on your page to place their order. However, the masking approach you're using can lead to other problems if you use our Cart buttons (our Buy Now buttons are not affected by this):
Each affiliate gets their own, unique Hop Link code from E-junkie Affiliate Admin; they must use this link (or at least the URL of the link) to refer buyers to your site. These links will refer all buyers to whatever landing page URL you have set up for your hop links. Buyers who click a Hop Link will be redirected to your landing page URL while our system sets a cookie in the buyer's browser that expires in 6 months. Every product that buyer orders via your E-junkie purchase buttons during the lifetime of that cookie will earn the referring affiliate a commission according to your specified share percentage.
This help page explains our affiliate system and related settings in detail:
We also have a help page for affiliates, explaining the system from their perspective: