This past holiday season set sales and profit records across the e-commerce industry, and that means investors should hear good news from eBay (EBAY -2.91%) when it posts fourth-quarter results on Wednesday, Jan. 31.

Sure, the online marketplace isn't growing at the blistering rate that many rivals are enjoying. But its asset-light operating approach still produces market-thumping profit growth -- even at a slower expansion rate.

With that in mind, let's look at a few trends investors can expect to dominate eBay's upcoming report.

A man types his credit card information into a laptop.

Image source: Getty Images.

Buyers and sellers

eBay's most recent quarterly announcement showed a 7% sales volume boost in its core marketplace segment. Sure, that's far below the 50% spike that Wal-Mart Stores (WMT 0.48%) enjoyed in its e-commerce channel, or the 23% increase (AMZN -0.09%) managed. But the result matched eBay's best pace in over three years and kept the company on track for a modest growth acceleration in 2017, just as management had predicted at the start of the year.

CEO Devin Wenig and his team are forecasting roughly the same 7% growth over the critical holiday shopping quarter. Looking beneath that headline figure, the sales gains should show solid momentum in eBay's user pool, which has expanded at a 5% rate in each of the past three quarters, compared to 2016's 4% uptick. eBay's position as a vibrant marketplace depends on its continued ability to add to this big global base of shoppers.

eBay simply connects buyers with sellers, and so -- as opposed to integrated retailers like Wal-Mart and Amazon -- its main source of profit is the transaction fees it charges sellers rather than product markups. That so-called "take rate" has been edging higher recently, rising to 7.8% over the last six months compared to 7.7% for the full fiscal 2016 year. Another quarter of improvements here, or at least steady results, would show that its efforts to improve seller services are paying off.

Finances and outlook

eBay's sales growth rate might look tiny compared to peers, but there are a few important financial rewards associated with its choice to leave expensive things like shipping, warehousing, and delivery up to its individual sellers. That selling platform approach translates into a nearly 30% profit margin, for example, compared to less than 5% for both Wal-Mart and Amazon.

EBAY Operating Margin (TTM) Chart

EBAY Operating Margin (TTM) data by YCharts.

Investors should also benefit from the fact that almost all its operating earnings convert directly into free cash flow. In fact, eBay generated $720 million of cash last quarter, or about 30% of its revenue base.

Management's full-year targets call for sales to rise to $9.55 billion, or a bit more than the $9.4 billion they had originally projected. Look for free cash flow for the year to come in at $2.3 billion to mark an improvement over the $2.2 billion it generated in each of the last two fiscal years. And on the bottom line, eBay should post $2 per share of earnings, or 6% better than 2016's result.

The company's outlook for the 2018 fiscal year will be critical, since it conveys how Wenig and his team view the competitive marketplace. Steady volume gains would likely translate into more financial wins and, perhaps, shareholder-friendly moves like a divided or increased stock repurchase spending.

If holiday sales growth was disappointing, on the other hand, eBay might decide to rein in its profit outlook as it prioritizes improving the service in 2018.