Facebook Preferred Marketing Developer Extole today announced that it has raised an additional $7.6 million in funding.

Extole, which bills itself as a “social advocacy platform,” helps brands and agencies promote engagement across the web, email and social networks like Facebook through apps meant to drive word of mouth. Last year the company released new products and updated existing ones to integrate Facebook’s Open Graph publishing features, which increase virality and earned media. One client found that for every one person who entered the sweepstakes after seeing a promotional message from the brand, 3.6 additional people entered as a result of social recommendations.

Extole says it has seen significant growth in revenue, bookings and customer acquisition over the past year, including winning new clients like eHarmony, Spotify, Cache, Seventh Generation and HSN Improvements. T-Mobile, Shutterfly, Redbox, SkyMall and Seamless are among Extole’s other customers.

This latest funding comes from Extole’s previous investors Shasta Ventures, Norwest Venture Partners, Redpoint Ventures and Trident Capital, who participated in a $10-million Series C in February 2012. Extole has raised a total of $29.6 million since September 2010. Extole says the funding will be used for product and platform investments, as well as company growth.