They are getting a double discount but from only one place. Orbitz will match Disney's general public discount and offer the same percentage off on their website. Then they will often run a special offer that is additional discount which you only receive if you use their promo code when booking the room. I was looking at Orbitz's website last night and saw some Wilderness Lodge rooms at a 25% discount, the same discount Disney is offering for that time period. Then if you use the promo code, they gave you an additional $150 off the reservation. That is what people mean by getting a double discount.