Amazon.com is a highly addictive experience. And Amazon Prime (all the free shipping you can eat for $79 a year) has brought the term crack to more than a few shoppers’ lips, including my own. Once I signed up for Prime, Amazon became the first place I’d look for anything I needed — literally anything ranging from statues of Buddha to cat food.

As a three-cat owner, I was delighted to discover the company selling and willing to ship me our favorite brand of cat food, in the right sized cans, at a good price, as part of the Prime program. And so, for the past six months, the Rosenblum cats have been happily munching on organic Turkey and Vegetables. It makes up about half their daily diet. Imagine my surprise when I tried to place an order two weeks ago, and was informed I’d bought the maximum quantity allowable — ever. The quantity ordered was reduced to zero.

So here I am, having a customer service problem with the putative on-line customer service champion. I rooted around the site and found a customer service number. I called it and found myself talking to someone on the other side of the world (probably Indonesia, but I don’t even ask anymore) who read me a script, basically repeating what I read on the web site. I followed with two emails. I did get two replies, but the answer was stunning.

A quantity limit is the maximum number of any item that can be purchased by a customer. We want as many customers as possible to be able to enjoy the items we sell, and so for some popular items we’ve limited the quantity that may be purchased from our store. “

We had a few more email exchanges where I was assured that the quantity limit could not be raised. Was it stunning that there’s a quantity limit? Of course not. The price is definitely lower than in stores and the cans are heavy. What IS stunning is that there is no mention ANYWHERE on the site that this quantity limit exists. This, from the technology champions? It was like a crack dealer suddenly withdrawing my drug. Obviously, cats gotta eat so I bought the case through Amazon’s marketplace (paying shipping), and subsequently created a repeating order with some other on-line retailer. I got a discount for creating a regular order (and before you ask…yes, I’d tried to do the same on Amazon).

Ironically, while writing this piece, I made an attempt to order the same food again. My order magically went through. Oops. Between all my alternative sources, I’m about to be awash in Newman’s Own Turkey and Vegetable cat food. Perhaps some set of analytics realized that I just bought it from a Marketplace provider. The technology worked just fine then. In fact, a friend of mine insists that if you want to get a deal from Amazon, browse certain items and maybe even put them in your shopping cart and abandon the cart. Within two-three days, he claims, you will get an email from Amazon offering a special on the very same products. He might well be right. So the company has the sophistication to do that, but can’t put up a small note about quantities being limited? That’s just bad.

I kept wondering, “What are they thinking? “ The cats aren’t going to change their diets. I’m just going to buy elsewhere. And when I did look around, I found deals that were close enough to the original Amazon deal. Putting my retailer hat back on, I had to say — that is one seriously unfortunate move for a retailer that wants to start selling me my groceries, and ultimately deliver them to me too. In the end I had to ask myself, “What were they thinking? “

Is this a crack in Amazon’s armor? Is it nature’s way of telling me not to get too invested in the crack we call Prime? It reminds me of the old story, “For want of a horseshoe nail, a kingdom was lost. “ It’s the small things that break retailers’ holds on their customers.