E-commerce giant Alibaba is slated to go public Friday, and the Alibaba IPO is expected to be one of the largest deals (if not the largest) in history.

That’s not really a surprise, considering the online retailer does more transaction volume than U.S. giants like eBay (EBAY) and Amazon (AMZN), and its success has even given struggling Yahoo (YHOO) shares a noticeable boost over the last year or so.

Lots of investors don’t know much about Alibaba, though, because comparisons and exaggerations are floating around everywhere. Many are even saying that Alibaba is like Amazon, eBay and Google (GOOG) all rolled into one because of its breadth of services.

Right now, though, we’re going to zoom into one sliver to see what tangible takeaways there are for potential Alibaba IPO investors.

Recently, Bernstein Research shared some numbers from Yipit Data about the “marketplace” part of the Alibaba equation: two websites called Taobao and Tmall.

In case you aren’t familiar with those sites, Paul J. Lim of Time.com gave a good summary of one in a recent piece previewing the Alibaba IPO. He describes Tmall, through a comparison with competitor JD.com (JD), as “an online marketplace where other sellers can find consumers — much like Amazon (AMZN).”

Yipit Data dove deeply into these two Alibaba marketplaces Taobao and Tmall, analyzing details like transaction history and pricing for each SKU, seller ratings, return rates and commission fee structure. For some context, Tmall has gross merchandise volume of about $100 billion, while Taobao has nearly doubled that figure over the past 12 months. Unsurprisingly, though, the smaller Tmall also is growing much faster than its larger counterpart.

So what did Bernstein Research and Yipit Data find when they analyzed the two marketplaces? Here are three things investors might want to be aware of before moving on the Alibaba IPO.

1. Think about services. One thing that the analysts at Bernstein found surprising was the fact that services make up between 30% and 40% of gross merchandising volume for the smaller but faster growing Tmall. “Many people are spending a lot of time thinking about penetration of e-commerce or Alibaba over Chinese consumption,” the report reads. “Yet, the data suggests that it is important to realize that services are a material element of gross merchandise volume.” The analysts went on to suggest that this could mean headroom for higher growth for both sites.
2. Watch mobile. One thing to note: This data analysis is just beginning, and provides more of a starting point rather than trends or meaningful comparisons. Still, it’s useful to note that somewhere between 12% and 14% total gross merchandising volume for the two marketplaces came from mobile-only promotions. Considering the unmistakable mobile mega-trend, this is a figure to keep an eye on.
3. Seriously … watch mobile. Mobile isn’t just important in terms of how the sites are selling, but in terms of what they are selling. The report notes that “mobile services” — which are essentially prepaid cell phone minutes — was the largest category for gross merchandise volume in the second quarter, stealing around 18% of the pie. Again, this reality ties back to the first bullet point showcasing “services,” but provides a bit more color as to what kinds of services are out there.

All in all, the lesson is pretty clear: As earnings reports begin rolling out following the Alibaba IPO, don’t overlook the services segment or mobile — whether in terms of a selling platform, advertising platform, or product itself. While there’s lots of hype surrounding the IPO, those are the details some key parts of the company are built on.

As of this writing, Robert Martin did not hold a position in any of the aforementioned securities.