ValueClick Inc. on Wednesday announced plans to add more than 100 employees in its primary markets as part of an organic growth strategy for its online advertising services.

The Westlake Village company, which provides online advertising campaigns and programs, said the 10 percent staffing increase will fill sales, business development and technology positions primarily in Los Angeles, New York, San Francisco, Chicago, and Boston. There also are openings in some secondary U.S. markets and in Europe and Asia.

ValueClick in regulatory filings said that it had 1,062 employees at the end of last year. Its earnings beat expectations in the last few quarters, and the company in April added to its mobile advertising business with the $70 million acquisition of Greystripe Inc., whose platform is used by companies to direct ads to cell phones and other mobile devices.

“With our recent expansion of video and most recent acquisition of Greystripe mobile advertising, we are serving a much broader market,” Chief Executive Jim Zarley said in a statement. “We need additional intelligent, motivated go-getters to keep up with our momentum.”

The company cited a recent report by market research firm eMarketer, which expects online advertising to generate $31 billion in revenue this year, a 20 percent increase. Mobile advertising revenue alone is expected to top $2 billion by 2013.

Shares closed up 47 cents, or 2.8 percent, to $17.30 on the Nasdaq.