USamp announced on Monday that it has received a $15 million investment from two private equity firms to enhance the marketing company’s online services.

The Encino company, which assembles panels of consumers to test products and services for corporate marketing departments, will use the funds for its Instant.Ly website. The service provides real-time feedback from panel testing and allows corporate marketers to manipulate the data.

“The need to make sense of and act on changes in consumer behavior is placing a premium on insight products that are easy to access and that offer our clients multiple ways to understand their markets and interact with their customers,” said Chief Executive Alan Gould in a statement.

OpenView Venture Partners in Boston and DuPont Capital Management in Wilmington, Del. participated in the Series D funding round.

Previous institutional investors include Greycroft Partners in Santa Monica and DFJ Frontier in Sherman Oaks.

The company has a panel of 12 million online survey respondents. Clients include General Mills Inc., Google Inc. and Microsoft Corp.