Yeah, occasionally, the merchant might get antsy if you tried seven coupons for seven items. But, normally, the merchant gets to submit the coupon so he usually couldn't care less. Provided that he has more stock than coupons, it really makes no difference to him.

What the individual on the other forum is attempting to convey is the fact that the manufacturer may attempt to limit the use of the coupon to a single purchase by a single individual. In reality, he has no control if you walked out of the store, walked back in, and bought another item with another coupon. The merchant usually recognizes this as well and probably will let it go.