What happened

Shares of Criteo SA (NASDAQ:CRTO) rose as high as 20% early Wednesday, settling to trade up 9% as of 3 p.m. EST after the advertising-retargeting specialist delivered better-than-expected fourth-quarter results.

Criteo's quarterly revenue excluding traffic acquisition costs (ex-TAC) declined 2% year over year to $272 million -- well above guidance provided in October for between $256 million and $262 million. That translated into a 31% decrease in adjusted net income to $56 million, or $0.84 per share, which also exceeded the $0.73 per share most investors were anticipating.

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Image source: Getty Images.

So what

Criteo increased its number of clients by 7% year over year to roughly 19,500, helped by a healthy client retention rate of 90%. Criteo also noted that 13% of its live clients are using at least two of its products, up from 4% in the same year-ago period. 

"Our Q4 results mark an inflection point in our trajectory," stated CFO Benoit Fouilland. "We expect to see positive momentum in 2019 driven by healthy fundamentals and our broader multi-solution platform."

Check out the latest Criteo earnings call transcript.

Now what

To that end, Criteo expects first-quarter 2019 revenue ex-TAC of between $233 million and $235 million, marking modest growth of 1% to 2% in constant currency and comfortably ahead of consensus estimates for revenue ex-TAC closer to $231 million. Finally, for full-year 2019, Criteo sees revenue ex-TAC growth accelerating to between 3% and 6% at constant currency. 

Between that encouraging outlook and Criteo's relative outperformance to end 2018, it's no surprise to see the stock soaring in response today.