I order Seamless quite often. Especially when I have all of these $10 off $15 coupons. Although these coupons say they are for specific restaurants, they're actually usable for anywhere. A sandwich shop near my apartment gives stacks of these coupons freely.
However, these coupons only work on "new" accounts. The creation of these accounts is a special ritual for me. The process of getting a great discount and delicious food excites me like no other. The fact that I have to hit a $15 dollar minimum is great. It lets me order things I normally would not, sometimes getting a little fancy.
One negative is that this is not healthy for me. I used to be unable to finish $15 of Seamless delivery, but lately I've been completely finishing each meal. I also realize that this is not a good thing I'm doing. I am cheating a flaw in Seamless's system. So to feel better about myself, I always give a generous tip to the delivery person. But not too generous since I still want to save money. I'm a bastard.