I went to Which Wich the other day. I used a free sandwich coupon to get a pastrami with coleslaw and russian dressing plus tons of veggies, and the check out guy gave me a "Road to Wiches" card to register. I just registered it. Now, I get another free sandwich on my next visit. No coupon to print out. I just bring my card. I am also signed up for their mailing list. We'll see what is in store.
Pretty much, you get a free sandwich for every $75 you spend. There are a lot of $2 off coupons floating around.