Gareth Steven Collins

Part of Publicis Groupe SA, Holler Digital Ltd. is a British company that provides advertising services. The company is based in London, UK. Founded in 2001. Holler Digital was acquired by Publicis Groupe SA on February 17, 2011.

Leo Burnett Ltd. provides advertising services. It specializes in digital, social media, content, sales promotion, direct marketing, event management, and licensing and luxury branding. The company was founded in 1967 and is headquartered in London, the United Kingdom.