I don't think it's absurd at all. As other commenters have mentioned, seeing the coupon code box and not having a coupon gives me (personally) a feeling of remorse before I've even bought what I was shopping for. This should concern you, as a merchant, because ideally you'd like your users to associate good feelings with shopping on your site.
Beyond the "feelings" aspect, I suspect that, as is argued in the article, the coupon code box does lead in some cases to cart abandonment. I've certainly seen the box, gone on a hunt for a coupon, and ended up buying the same item at a different vendor during my hunt many times before.
Personally, I think the best solution for this is either special urls (i.e. www.shop.com/summercoupon), or a "Where did you hear about us" box, which could double as a coupon box, and just an interesting way to gather data about your users. Sure, you'd probably get a lot of garbage, and you'd have to put more effort into parsing the values, but, in addition to not alienating users, you might find some valuable insights as well.
What people say and what people pay are not strongly correlated. :-)
Coupons can give a 100-10,000% lift very easily, enabling web merchants to be less dependent on black Friday/cyber Monday/etc. They can shift demand earlier in the year to even out fulfillment stress and reduce the uncertainty in sales projections.
In the face of realized revenue vs. some perception of unhappiness, sales and marketing will take the buck eleven times out of ten.
Beyond the "feelings" aspect, I suspect that, as is argued in the article, the coupon code box does lead in some cases to cart abandonment. I've certainly seen the box, gone on a hunt for a coupon, and ended up buying the same item at a different vendor during my hunt many times before.
Personally, I think the best solution for this is either special urls (i.e. www.shop.com/summercoupon), or a "Where did you hear about us" box, which could double as a coupon box, and just an interesting way to gather data about your users. Sure, you'd probably get a lot of garbage, and you'd have to put more effort into parsing the values, but, in addition to not alienating users, you might find some valuable insights as well.
[edited for grammar]