One of L.A.’s fastest-growing private companies has named a new chief.

USamp, an Encino online survey provider, announced Tuesday that it has appointed Alan Gould as chief executive. He replaces uSamp co-founder Matt Dusig. Dusig will become co-president alongside co-founder Gregg Lavin.

“We are excited to welcome Alan to his new role as CEO,” Dusig said in a statement. “We are certain he will bring great energy and leadership to our already strong team.”

Gould founded IAG Research in 2000 and saw the company through its acquisition to Nielsen Co. for $250 million. He is currently a venture partner in the New York office of Greycroft Partners, which is an investor in uSamp. Gould became a uSamp director last summer.

USamp was founded in 2008 as a survey panel that can be tapped when clients want research conducted. The company, which has a panel of 12 million respondents, also provides back-end survey technology to companies such as J.D. Power and Associates.

The company was No. 9 on the Business Journal’s list of fastest-growing private companies in November with 2011 revenue of $36 million, up 321 percent over a two-year period. Its more than 200 employees work in five offices around the world.

“USamp is one of the fastest growing companies I have ever seen in the marketing services space with a special talent for introducing great technology to its clients,” Gould said. “I look forward to working with Matt and Gregg and this special group of innovators to expand our position as a go-to provider of key business insights.”