When protesters in Ukraine decided they'd had enough of the since-ousted administration in Kiev, it set in motion a series of events that many believe is destabilizing Russia and parts of Eastern Europe.

Companies based in that region haven't escaped unscathed, either -- foremost among them Yandex (NASDAQ:YNDX), parent company to Russia's largest and most popular Internet search engine. Shares of the company are down 40% since the crisis came to a head, even though its business has continued to perform well.

With Yandex set to report earnings before the market opens on Thursday, here are four things for investors to keep their eyes on.

1. The basics
If Yandex's shares make outsized moves following its earnings release, it will likely be due to short-term results or forecasts for the next quarter. We Fools prefer to focus on the long term.

That being said, it's worth noting what Mr. Market anticipates in order to understand any big swings in the stock price. Here's what analysts expect the company to announce for the third quarter, and what they're hoping the fourth quarter will look like.

Q3 Revenue

Q3 EPS

Q4 Rev. Forecast

Q4 EPS Forecast

$312 million

$0.26

$370 million

$0.32

Source: E*Trade.

2. Growth in core advertising
Yandex counts on text-based advertising for the vast bulk of its revenue. Throughout the crisis in Ukraine and the imposition of Western sanctions on Russia, the company has maintained steady growth in this realm, an impressive feat.

Here's how the company has performed since the end of 2012 with this key metric.

While growth has slowed somewhat in the past four quarters, this likely has much more to do with harder comparisons. Simply put, the company can't maintain 40% growth forever.

If Yandex can maintain a 35% growth rate in this market, it would equate to about 12.6 billion rubles, or $307 million for the quarter. It would also be a huge win for the company.

Sanctions imposed by both the United States and the European Union have suspended some international business dealings with Russia, and significantly slowed the pace of potential investment in the country. Russia's decision to ban food imports has also led to a significant rise in grocery prices, putting pressure on an already sluggish economy. If that weren't enough, oil prices have been falling rapidly, and the country counts on oil more than any other nation to stay solvent.

3. Are businesses still adopting the platform?
Only about 50% of Russian citizens have regular access to the Internet. That means there's still a long runway for growth in the online advertising business. It also helps explain why Yandex has grown its list of advertising partners at an average pace of 24% over the last two years.

Maintaining that 24% growth rate should be far easier than meeting revenue expectations. That's because Yandex can simultaneously gain customers but see them slow spending.

The company should be able to report that the total number of advertisers has grown to 310,000. Should it fall short of that number, investors should listen closely to the conference call to find out what caused the slowing of advertising adopters.

4. Most important, is Yandex maintaining market share?
The previous two metrics represent medium-term pressures that investors need to watch. But tensions over Russia's role in Ukraine will ultimately pass, though it's impossible to tell if that is months or years away.

When that day does come -- and business fears are alleviated --Yandex shareholders will want to know they still own a piece of the country's dominant search engine. That's why keeping an eye on market-share trends is so important.

Below is a breakdown of Yandex's market share within Russia, by overall Internet search and by mobile operating systems.

Keep in mind that Google (NASDAQ:GOOG)(NASDAQ:GOOGL) is the second-leading search engine in the country, with 26% market share. That's a dangerous opponent to have to fend off, and shows why it is so important that Yandex keep its overall share north of 60%.

Just as important, Yandex has made huge strides in becoming the go-to search engine on Android smartphones within the country. That's a big deal, because Android users usually default to Google for search, and Yandex's 54% share on Android devices is a major advantage that the company can't afford to lose.

Keep your eye on these four metrics -- which range from short to medium to long-term issues -- and you should have a good bead on what's happening with the company.

Brian Stoffel owns shares of Google (A shares), Google (C shares), and Yandex. The Motley Fool recommends Google (A shares), Google (C shares), and Yandex. The Motley Fool owns shares of Google (A shares) and Google (C shares). Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.