Several months ago I made a bold statement: Amazon.com, Inc. (NASDAQ:AMZN) was taking on too many disparate projects. It was a daring claim simply because AMZN stock was (and still is) dancing with new highs. I stand by my theory though.

That is, there will come a time when Amazon’s mission of being all things to all people makes the company vulnerable to the inherent sloppiness of running a variety of unlike businesses.

Just earlier this month I added a nuance to the argument: while its online retailing businesses were getting bigger in terms of revenue, the AMZN stock profitability was shrinking.

Amazon Web Services was not only carrying the bulk of the weight in terms of earnings, it was driving all of the company’s profit growth, and then some. That too, however, was a vulnerability.

Some data has surfaced in the meantime that’s validated my concern. If you’re a fan of, or owner of, AMZN stock, this should bug you.

Slipping Through the Cracks for

To reprise the pessimistic point of view on today of all days feels a little out of place. Amazon just officially opened its convenience store of the future, allowing patrons to check out without actually pushing their purchases through a barcode-scanning cash register.

Cameras and sensors know what you picked up, and even what you put back.

It’s clever to be sure, and if nothing else provides great publicity.

The prototype store, however, only augments my concern from July. That was:

“There will come a time when the company has so many different balls to juggle that it ends up dropping them all. We may be nearing that point if we’re not there already.” I added there were “a variety of pairings that could – and likely will – start to develop now that the e-commerce giant has made it clear it aims to conquer the world… So far none has occurred, with most large corporations preferring to do things on their own. Amazon’s increasing dominance is undeniable though, and its competitors are finally, tacitly starting to open their minds to new ideas.”

The two biggest threats I saw at the time were Wal-Mart Stores Inc (NYSE:WMT) and Microsoft Corporation (NASDAQ:MSFT).

It’s not surprising that both threats have solidified as threats in the meantime, capitalizing on the sheer difficulty Amazon has in managing a beast of its size and its distracting variety of operations.

On the cloud computing front, Amazon’s dominance of that market may soon be at an end. Per its report posted earlier this month, KeyBans says Amazon Web Services’ market share of the cloud market slumped from 68% to 62% in the fourth quarter, lost to Microsoft.

It’s not the end of the world if you own AMZN stock. The cloud computing market is growing faster than Amazon is losing market share. That won’t always be the case though. It’s increasingly becoming a commodity as we move closer to the point of saturation, and AWS has proven it’s not the end-all, be-all choice.

As for Wal-Mart Stores, it’s still nowhere near the e-commerce machine Amazon is, but last quarter’s e-commerce sales were up 50% for the world’s biggest retailer. That’s revenue that arguably should have been (and otherwise would have been) Amazon’s and would have even better driven AMZN stock.

Bottom Line for AMZN Stock

With all of that as the backdrop, don’t misread the message. This isn’t so much about what Microsoft and Wal-Mart are doing right. It’s more about what Amazon is missing.

In its quest to own the world, it may well be struggling to juggle all the different balls it’s currently got in the air.

Between a budding bookstore chain, cloud computing, an international e-commerce arm that’s losing more and more money, the convenience store experiment, the cultivation of a hand-crafted venue not unlike the one operated by Etsy Inc (NASDAQ:ETSY), (and more), the company may have bitten off more than it can chew.

In fact, just a few days ago Whole Foods workers lamented too many empty shelves and inventory problems. The fingers of blame are pointing in all directions, but by and large it looks as if Amazon has been trying to run its grocery stores using the same kind of inventory management approach it uses to run its e-commerce warehouses.

It simply doesn’t work. The company’s top brass should have known that, but may have been too distracted by everything else on their plate.

In other words, things are starting to get more than a little messy the bigger Amazon’s web gets. They’re not yet, but owners of AMZN stock may ultimately end up paying the price. So far, margins have thinned rather than widened as the company’s gotten bigger.

Just food for thought, since getting actual food to eat at Whole Foods has become something of a challenge.

As of this writing, James Brumley did not hold a position in any of the aforementioned securities. You can follow him on Twitter, at @jbrumley.