NEW YORK & LONDON--(BUSINESS WIRE)--WPP (NASDAQ: WPPGY), announces that it has acquired Medialets Inc. (“Medialets”), creator of technology that helps marketers manage and measure the complete return on investment of mobile ad campaigns. Medialets’ clients include American Express, HBO, Johnson & Johnson and SKY Sports television. The company employs almost 50 people and is based in New York with sales operations in Los Angeles, Chicago and London. Medialets was founded in 2008. This acquis