Online real estate specialist Zillow (NASDAQ:ZG) is set to announce fourth-quarter 2014 results soon, meaning it's time for investors to think about what to expect.

Wall Street is looking for adjusted fourth-quarter earnings of $0.28 per share and revenue of $90 million. The revenue figure is at the high end of guidance Zillow provided in its solid earnings report three months ago, when it said revenue would grow roughly 53% year over year to a range of $89 million to $90 million. 

But to understand Zillow's burgeoning business, investors need to look at more than just revenue and income. Here are three questions I'll have at the ready going into Zillow's quarterly report.

How fast is mobile usership growing?

In the previous quarter, Zillow enjoyed a company-record 86 million average monthly unique users, good for an increase of 41% year over year, including a new record high of 89 million in July 2014. Most notable within those results was that mobile visits jumped 70% year over year, with roughly 500 million homes viewed on Zillow through mobile devices in September alone. That's up from 400 million homes viewed from mobile devices in January 2014, when Zillow also noted mobile users nearly doubled year over year to represent over two-thirds of its total visits.

While year-over-year growth in mobile might decelerate, Zillow ideally will demonstrate a sustained trend of growing and monetizing the increasing number of mobile views. Investors are fair to expect as much considering what CEO Spencer Rascoff described last quarter as Zillow's "consumer-focused mobile first strategy."

Are real estate pros embracing the new services?

Next, last month Zillow effectively doubled down on real estate professionals by forming a new customer support team designed specifically to cater to their needs. Zillow also launched a new listing management and reporting platform called the Zillow Data Dashboard. The new platform will directly connect with "just" 1.6 million for-sale-by-agent listings to start, but is expected to eventually handle all new listings published on the site.

These efforts weren't terribly surprising, as Zillow not only added 4,059 net new Premier Agent advertisers last quarter alone (bringing its total to 60,877), but also increased its net revenue per advertiser by 32.2% year over year to $349. What's more, agents using Zillow's platform for over a year spent 65% more than in the same year-ago period. And only a few weeks ago, Zillow stock popped when the company announced Zillow Pro for Brokers had impressively exceeded the 5,000 partner mark.

This is especially important as revenue growth from Zillow's display business is expected to decelerate to a year-over-year rate of 20% in the fourth quarter, thanks to reductions in advertising spending by financial institutions. That's better than the growth of the broader display industry, but Zillow CFO Chad Cohen insisted management is happy "underinvesting" in the display business given the superior growth to be had through the Premier Agents platform. To capitalize on that growth, however, Zillow needs to show real estate professionals are responding positively to its new services.

How is the Trulia purchase progressing?

Last but not least, I want to hear more details on the progress of Zillow's impending acquisition of Trulia (NYSE: TRLA). Three months ago, Rascoff told shareholders the company had certified compliance with the Federal Trade Commission's second request for information regarding the purchase, and remained optimistic the deal would close in the first half of 2015.

That said, note that on Feb. 3, 2014, Zillow confirmed the timing of its fourth-quarter 2013 report, then officially announced those results on Feb. 12. But as of this writing Zillow has still yet to even schedule its upcoming conference call to discuss fourth-quarter 2014 results. I can't help but wonder whether the delay is primarily due to pending news regarding completion of the Trulia acquisition. If that is the case, I wouldn't be the least bit surprised if Zillow prefaces its official earnings release with such an update.

In the meantime, investors are left to hurry up and wait for Zillow to schedule its call. When that happens, you can be sure we'll be here to let you know how Zillow fares.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.