Publicis has added to its network Outside Line, a U.K.-based experiential and social marketing agency, and will keep its management and integrate it within Saatchi & Saatchi. Clients of the agency include British Gas and Virgin Galactic. The move comes a week after Publicis acquired iStrat, an Indian digital shop, and continues a spate of acquisitions by Publicis and WPP, which are racing to scoop up the last remaining independent digital shops.