What happened

Shares of QuinStreet (NASDAQ:QNST) are trading 18.4% higher here at 3:20 p.m. EDT, following the online marketing specialist's first-quarter earnings report.

So what

QuinStreet's third-quarter revenue rose 29% year over year to $113 million, nearly doubling the bottom line from $0.08 to $0.14 per diluted share. The Street consensus had been pointing to earnings near $0.13 per share on sales in the neighborhood of $103 million.

Encouraged by this quarter's solid results, management also raised their full-year revenue target. Fiscal-year 2019 is now expected to see between 15% and 20% revenue growth, up from an earlier 10% guidance marker.

A man holding up a white posterboard with the words Digital Marketing in the middle and arrows pointing to various related keywords such as Like, Internet, SEO, and Followers.

Image source: Getty Images.

Now what

The company enjoyed double-digit sales growth in all of its reported client categories, paired with widening profit margins to generate even faster-growing earnings. QuinStreet's focus on digital and online marketing campaigns serves it well as clients move larger and larger portions of their advertising budgets off of old-school alternatives such as billboards and print ads and into QuinStreet's wheelhouse.

In particular, the all-important financial services sector delivered 32% year-over-year revenue growth and represented 69% of QuinStreet's total sales. Within that segment, management saw strong demand for insurance campaigns but a softer mortgage market.

Including today's big jump, QuinStreet's shares have crushed the broader market with an 86% gain over 52 weeks. The stock still looks relatively cheap at 16 times forward earnings, especially in light of these fantastic growth trends.