Amazon (AMZN 0.26%) is an online retail powerhouse, selling and delivering its own products and acting as a middleman for other retailers. The company's delivery trucks are ubiquitous in some areas of the country. But it has even bigger aspirations when it comes to getting products to customers.

So why did United Parcel Service (UPS -1.85%) decide to stop handling as many Amazon deliveries?

Image source: Getty Images.

The Amazon and UPS breakup

As with any good breakup drama, the story between Amazon and UPS, as United Parcel Service is called for short, is hard to call. UPS says that the Amazon business it was doing was high volume, but low margin. That meant that it didn't add enough to the bottom line to make it worth the top-line benefit. UPS says it plans to step away from half of the business it does with Amazon over the next couple of years.

That effort is in keeping with UPS' goal of improving the quality of its business. But management highlighted that it will still work with Amazon on some things.

Notably, Amazon is increasingly good at delivering its own wares, but it doesn't have a strong handle on returns. With a large retail store network, UPS can still provide return services to Amazon at an attractive return for UPS shareholders.

So the relationship isn't dead -- it's just different. Or, you could say, they will still be friends.

Amazon is paying up to fill the gap

UPS' decision to put limits on its relationship with Amazon is a problem for Amazon. While it is true that Amazon has been growing its distribution capabilities, it now has to step up more quickly than it might have planned. To that end, Amazon recently announced that it was making a capital investment of up to $4 billion to enhance its ability to make rural deliveries. And it inked a deal with UPS' peer FedEx (FDX -1.10%), where that carrier will handle larger packages for Amazon.

The market saw all of this as a win for FedEx and a loss for UPS. For Amazon, it wasn't too big a deal, noting that the stock is widely adored on Wall Street right now. While Amazon's stock is about 15% below its all-time high, its price-to-sales and price-to-earnings ratios are both above their five-year averages. And they are both fairly lofty on an absolute basis, as well. Still, it looks a little like Amazon is scrambling to take on the distribution services that UPS is willingly giving up.

So what about UPS? The company's stock has lost more than half of its value since hitting a peak in 2022. In fact, it made the Amazon announcement just as it appeared it was getting its business back on track following a period of weakness that led to a corporate overhaul.

Indeed, revenue had started to grow and margins appeared to have stabilized. Moving away from low-value Amazon business was a preemptive move made at a time when UPS had shifted from business weakness to business strength.

In other words, UPS is being proactive because it sees the writing on the wall. Its Amazon business was going to keep shrinking anyway, so why not get ahead of it?

The costs Amazon is incurring to make up for the loss of UPS as a delivery service is a sign that this was a big deal. But it will be a bigger deal for Amazon than UPS, since UPS was clear that the business wasn't very profitable. In fact, UPS could end up the big winner if the ability to slim down allows it to further improve its margins, even if the top line of its income statement shrinks along the way.

Don't sleep on UPS as an investment

Wall Street loves Amazon, and perhaps for good reason. But the stock is trading with a premium price tag. UPS, which could actually end up being the big winner in its breakup with Amazon, is deeply unloved. Notably, its price-to-sales and price-to-earnings ratios are well below their five-year averages. The stock's dividend yield, meanwhile, is historically high at around 6.7%.

There's no question that UPS has extended the length of its turnaround by breaking up with Amazon. But the near-term pain could be exactly what it needs to rise up again. Contrarian investors, dividend investors, and value investors should all be doing a deep dive into UPS today with the idea of adding this unloved delivery service to their portfolios.