The agency has replaced LBi as the top-ranked agency, with AKQA, Publicis Chemistry and Iris making up the rest of the top five.
Noelle McElhatton, editor of Marketing, said: "While not registering the biggest growth rate amongst the top 10 agencies, Sapient Nitro has undergone a striking metamorphosis in the past few years.
It’s evolution from technology consultancy into leading digital ad agency, investing in creative talent and luring brands such as Sky, Ladbrokes and GlaxoSmithKline as clients along the way, has propelled it into digital’s top ranks."
Of those agencies ranked in the top 25, TH_NK and M&C Saatchi (UK) showed the biggest percentage change in turnover, with a 149% and 65.4% increase respectively.
For the first time, Marketing created sector-specific leagues – a ranking of agencies according to their strengths in the various disciplines of digital, including social media, email, mobile, e-commerce and eCRM.