I thing is early entrence to the sidewalk sales
I have also had them ask for my ITC card to use coupons in the store. you can also use the coupon online. And as Darryl pointed out you get early entrance to side walk sales, they also have sales just for ITC members.
It's well worth the money. I love mine with mine. For Christmas I was able to get there meat slicers for my entire family for $20.00 a piece (I could not find any other place for under $60.00 a piece) I bought a total of 8 of them and had them mailed out for $10.00 Each for shipping.