Shares of Duolingo (DUOL 3.64%) rose by 33.6% in February, according to data from S&P Global Market Intelligence. A thoroughly Street-thumping earnings report erased the language-learning expert's prior price drop, which started around the holidays.

Duolingo's Q4 by the numbers

Your average Wall Street analyst expected the company would report fourth-quarter earnings of roughly $0.17 per diluted share on sales near $148 million. In actuality, it generated earnings of $0.26 per share on revenue of $151 million. In other words, its 45% year-over-year revenue growth outpaced the Street's expectations by a hair while the bottom line swung up from a $0.35 loss per share much faster than expected.

More importantly, Duolingo presented stellar growth in its user and subscriber metrics. Monthly active users (MAUs) rose 46% from the year-ago period while the more deeply engaged daily active users (DAUs) increased by 65%. Most of Duolingo's users are still on its ad-supported free plan, but the count of paid subscribers also jumped 57%.

The green owl's long-term ambition

Duolingo's 2023 was all about innovation. It launched math and music courses (exclusively for users on the mobile iOS platform for now, to be followed by web-based and Android versions later), plus innovative features driven by artificial intelligence (AI) that arguably rival real-life tutors.

The numbers don't lie. Duolingo saw massive user growth and became significantly more profitable last year. Its focus on a fun, engaging product pairs well with its low-cost marketing strategy that's mainly focused on a brilliantly managed social media presence. I'm sure you've seen Duo, the company's green owl mascot, which made an irreverent appearance in this year's Super Bowl ads.

In the long run, Duolingo CEO and co-founder Luis von Ahn wants to "develop the best education in the world and make it universally available." That's an ambitious goal, but one that seems well within Duolingo's reach when you look at its rampant business growth and innovative learning experiences.

The customer bases for its math and music services -- which are presented in the classic Duolingo format -- are already growing faster than its language service did in the early days. Expand that success to other topics for which learning by gamified repetition could be effective, and you could get a legit full-spectrum learning platform a couple of decades down the line.

The full development of von Ahn's expansive vision may take a while, but I'm here for it. Duolingo is one of my favorite stocks to buy right now, even after February's steep price jump.