SAN FRANCISCO - Online marketing services firm ValueClick ( VCLK) matched earnings estimates for second quarter, but the company guided the Street lower for its third-quarter and full-year results. ValueClick said it earned $16.5 million in the second quarter, or 17 cents a share, a drop from $17.6 million, or 17 cents a share, a year ago. That was in line with analysts' estimates. Revenue grew to $163.8 million in the second quarter vs. $148.7 million a year ago, falling 1% below the company's low end of guidance. Analysts had anticipated revenue of $165 million. "While increased macroeconomic uncertainty makes revenue growth more challenging for the second half of the year, we are taking meaningful steps to preserve margins and drive long-term growth and shareholder value," said Chief Executive Tom Vadnais in a statment. "We are accelerating initiatives to increase synergies among our businesses, and we have been active in our stock repurchase program since our July 17 pre-announcement. We believe ValueClick's long-term prospects are bright, and we are committing resources to realize the opportunities in front of us while driving bottom line results." For the third quarter, ValueClick expects to earn 14 cents to 15 cents a share on revenue in the range of $150 million and $156 million. Analysts had expected earnings of 16 cents on revenue of $162 million. The company reiterated its full-year revenue guidance of $655 million to $675 million and earnings in the range of 69 cents and 71 cents. That fell short of analysts' full year revenue guidance of $689 million on earnings of 74 cents. Shares of ValueClick were off more than 4% in recent after-hours trading to $11.39.