I've abandoned purchases as well. When I know I might be missing out on a coupon, I go hunt for it. Most of the time I don't find the coupon I'm looking for, but I do stumble across (coupons for) other products, which might offer a better deal. I end up purchasing those, or not purchasing anything anymore.

Instinctively I agree with the author: when a customer has effectively made a purchase decision, a webshop shouldn't divert him to random pages on the internet, unless there is a mechanism in place that leads to extra sales. Showing a coupon box during one of the final phases of the purchasing process is a way of diverting customers to random pages on the internet.

I've done the same. The coupon code box screams, "You're a sucker if you don't have a code to put in here."

I go searching for a code. I find a few great ones that have expired but nothing active right now. Now I can continue my purchase and feel like a chump or abandon my cart. The latter usually wins.

I’ve done the same - though in at least one case I did purchase eventually when I caught the promotion.

However that was still reduced and delayed revenue for the vendor over not having the box. And how many times have I completely given up… Lots.

I'd say that a coupon code box runs a distant third behind surprise high shipping rates and sites I've never heard of that don't accept third-party payment sites and instead want my credit card info. Nope.

Technically speaking, a credit card is a third-party payment system ;)

But, I still get your point. Ridiculous shipping charges has definitely led to me abandoning a cart more often then coupon code boxes. Although, I still prefer it when sites just tell me what the shipping is before I put the item in my cart. Not telling me before I have to fill in anything more than a zip code tends to be a sign of high shipping charges and sometimes leads to me going to a competitors website without even checking what it will cost to ship.

Another problem with coupon codes is they allow for affiliate commission stealing. Say someone visits a site via an affiliate URL and they are about to checkout when they notice the coupon code field. They Google coupon codes and find a site that says you have to use their URL (as many do). Now the coupon code site gets credit for the referral. On the surface this doesn't seem like a big problem but it is very common.

The worst I've had was the following:

- Go to buy a product, get all the way up to the checkout and abandon for an unrelated reason - Go back and purchase the product at full price - Get an email with a discount code for abandoning my cart the first time

Left a very unpleasant feeling of being stooged. If I'd only known to abandon my cart first...