Shares of Roku (NASDAQ:ROKU), the maker of the world's leading streaming-TV platform, are rising on Tuesday, ahead of the company's earnings on Thursday. As of 1:10 p.m. EST, the stock was up nearly 3%.

The market's bullishness for the stock isn't surprising. Both Roku's business and its stock have seen strong momentum recently. Trailing-nine-month revenue jumped 54% year over year and shares are up 190% over the past 12 months.

Ahead of Roku's earnings release Thursday, here's a look at some of the key areas investors may want to check on when the results go live.

A Roku-powered TV in an apartment living room

Image source: Roku.

1. Growth in Roku-monetized video ad impressions

Roku's recent strong revenue growth rates have been driven by robust strength in the company's platform revenue, or revenue from subscriptions, transactions, and ads on its platform. This revenue is key to the company's business model: Roku aims to get its players and TVs with built-in Roku streaming software in front of as many users as possible and subsequently monetize those users with ads and services available on its platform. It's working. Third-quarter platform revenue soared 79% year over year.

But investors should pay particular attention to platform revenue's most substantial catalyst: advertising. Management said in Q3 that Roku-monetized video ad impressions "more than doubled" during the period -- a growth trajectory that is consistent with prior quarters. Investors should look for similarly rapid growth in the company's monetized ad inventory in the fourth quarter.

2. Average revenue per user

Highlighting how successful Roku has been at monetizing its users, the company's trailing-12-month (TTM) average revenue per user (ARPU) is consistently rising. TTM ARPU in Q3 was $22.58, up 30% year over year and higher than the company's TTM ARPU of $21.06 in the second quarter.

In Q4, investors should look for this figure to rise once again both year over year and sequentially.

3. 2020 revenue guidance

Finally, investors should check on Roku's guidance for 2020 revenue. Trading at about 16 times sales, this growth stock is priced for more rapid growth in 2020 and beyond.

Analysts, on average, currently expect Roku's 2020 revenue to come in at $1.58 billion. Assuming the company achieves analysts' average estimate for 2019 revenue of $1.11 billion, analysts' 2020 forecast implies 42% year-over-year revenue growth.

Will Roku's 2020 revenue guidance live up to analysts' expectations? Such a high target would be impressive as it would only represent a modest deceleration from the streaming-TV giant's 50% year-over-year revenue growth rate in its most recently reported quarter. 

Investors can tune into Roku's fourth-quarter update after market close on Thursday, Feb. 13. The company will host a live question-and-answer session to discuss its financial results on the same day at 5 p.m. EST.

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.