What's happening: Shares of Criteo SA (ADR) (CRTO -1.11%) were down 11% as of 1:45 p.m. Tuesday after the performance marketing technology specialist reported mixed second-quarter results.
 
Quarterly revenue excluding traffic acquisition costs, or ex-TAC, rose 64% year over year (51% at constant currency) to 110.5 million euros, helped by the ongoing roll-out of Criteo's latest technology across all screens, 730 net client additions in Q2, and the continued expansion of its publisher relationships. That translated to 64% growth (60% at constant currency) in adjusted EBITDA to 21.8 million euros, and a 78% increase in adjusted net income to 9.9 million euros, or 0.15 euros per diluted share.   Analysts, on average, were expecting higher adjusted earnings of 0.17 per diluted share, and lower revenue ex-TAC of 107.8 million euros.
 
For the current quarter, Criteo anticipates revenue ex-TAC between 116 million euros and 118 million euros, and adjusted EBITDA between 21 million euros and 23 million euros. By contrast, Wall Street was modeling Q3 revenue of 115.9 million euros, and adjusted earnings of 0.27 euros per share.
 
Finally, for the full year 2015, Criteo raised its revenue ex-TAC guidance to between 470 million euros and 475 million euros, up from its previous range between 454 million euros and 460 million euros. At the same time, Criteo reiterated its adjusted EBITDA range of between 120 million and 127 million euros. Analysts were expecting 2015 revenue of 461.5 million euros, and adjusted earnings of 1.13 euros per share.

Why it's happening: The Q2 results were also above Criteo's previous guidance provided three months ago, which called for revenue ex-TAC between 105 million euros and 107 million euros, and adjusted EBITDA between 18 million euros and 21 million euros. Note Criteo did not offer guidance for earnings per share at the time.

Criteo co-founder and CEO JB Rudelle insisted, "We believe we are well positioned to capture the massive opportunity ahead of us."

"We have successfully executed on our growth plans for seven quarters in a row," added Criteo CFO Benoit Fouilland, referring to Criteo's initial public offering in late 2013, "and we will continue to invest in 2015 to maximize our growth potential."

Likely contributing to today's declines are worries over recent developer documentation from Apple hinting the Cupertino-based tech giant might soon implement ad-blocking features in its mobile Safari browser. In an interview with Business Insider shortly after today's report, however, Criteo COO Eric Eichmann noted the documentation simply enables third-party developers to build ad-blocking extensions, which means users will likely need to take the extra step of installing a separate app to serve the purpose.

"It's a very obscure type of app," Eichmann explained, "... This is not something Apple will be pushing or something that will become mainstream. So we are not worried because these kinds of things in the past have been available and never made any in-roads." What's more, Eichmann argued a built-in ad blocker for Safari mobile would damage Apple's ecosystem, as "many of these apps exist not because Apple pays them money, but because a lot of them are ad-supported."

All things considered, it appears to me Criteo is being unduly punished for what's otherwise another solid quarter.