NEW YORK (Real Money) -- My family, like many, has been shopping online for years, much of it though Amazon (AMZN - Get Report) , but also trying and buying from plenty of others.

We have a baseline on something that has simply become a way of life.

Every now and then, as with any business, there are screw-ups.

But lately those screw-ups appear to be on the rise, and I think I know why. My theory is that in the drive to keep margins from crashing to less than zero, the likes of Amazon are either hiring less-qualified warehouse workers, or workers are increasingly unhappy, or the companies are relying more on automation that might save money, but doesn't know how to pack the way humans do.

As for the bricks-and-mortar guys, like Best Buy (BBY - Get Report) , they simply haven't invested enough money into inventory systems to deliver on their promises.

Several recent examples, which seem to be rising with frequency:

  • Products, including books, from Amazon are arriving damaged. I recently asked my Twitter (TWTR - Get Report) followers about this. Some said they haven't noticed, but quite a few agreed that something has changed, especially with the way things are packed. (Good thing Amazon still has the best no-questions-asked customer service in retail to take away the sting. At Amazon, in our experience, the customer is always right.)
  • We've been buying from Drugstore.com for years, but ever since Walgreen (WAG) bought, it everything seems to be dumped into a box without packing materials.
  • My favorite. Over the weekend, I went to buy a phone case for my daughter that appeared to be available only at Best Buy. We bought the case online for pickup at one of two stores that showed available inventory. You can guess the rest of the story. Even though there were supposed to be two cases available, the store I went to couldn't find either. I called the other store. It supposedly had two, as well, but the store couldn't find them either.

Reality: As those of us who have been in online publishing since the beginning can attest, executing online is harder and more expensive than it looks. 

Just as a big cost is content-management systems for online publishers, in retail it's inventory, distribution and, for many, warehousing systems.

Increased competition requires a continued investment in technology. That costs money and that can be a challenge, especially for public companies, which are always under the gun to meet or beat the quarter. And the quarter we're in, for retailers, is the quarter. And this year, for online merchants, is (yet again) the year.

It's one thing to get the customers; it's another to keep them. Without solid execution, the latter is harder than the former.

All of this is worth keeping in mind as retailers report earnings next quarter. Rather than paying attention to the typical headline numbers, as the Street often does, it may make more sense to zero in on capital spending. That may be the best clue of all to who the real winners will be, assuming that's not just good money after bad in an industry that already appears to be a race to the bottom.

Herb Greenberg, editor of Herb Greenberg's Reality Check, is a contributor to CNBC. He does not own shares, short or trade shares in an individual corporate security. He can be reached at herbonthestreet@thestreet.com.