Greenberg leads the vision for R/GA, a 400 person New York based advertising agency centered in interactive media that services Fortune 500 companies and world-class brands. Known as a creative powerhouse, R/GA consistently blends effective strategies and in-depth technology to deliver optimized communications across multiple channels.

Greenberg, and his brother Richard, founded R/Greenberg Associates (R/GA) in 1977 with the idea of creating a company that valued design, while focusing on developing leading edge motion graphics and live action film and video production. The company created such ground breaking visual effects for "Alien", "Predator", "Seven" and "Zelig". R/GA's body of work spans 400 feature films and 4,000 television commercials.

He successfully transitioned the company into a multi-platform advertising agency, specializing in database-driven information and multichannel marketing and e-businesses. Clients include Avaya, Bank of America, Bed Bath & Beyond, Circuit City, Intel, Lowe's, Nike, Nokia, Purina, Reuters, Subaru, Target and Verizon.

Greenberg has forged a unique interdisciplinary approach to communications, promoting integrated teams of creative talent working side-by-side with highly skilled software developers, strategists and project managers. Along the way has won almost every industry award for creativity including the Academy Award, Clios and Cannes Lions. Among his most notable awards is the Cooper-Hewitt National Design Award for Communications in 2003 and the Chrysler Award for Innovation in Design that was accompanied by a show of R/GA's work at the San Francisco MOMA. He was the 2004 Cyber Lions Jury President in Cannes and is a member of the 2005 Titanium Jury.

Greenberg serves on the boards of numerous schools and organizations focused on the importance of design and the creative process. He is President of the Art Directors Club and is on the Board of Directors for the Brooklyn Academy of Music, Dean's Council Advisory Board of Tisch School of the Arts, Parsons School of Design and VCU Adcenter.

Over the years Greenberg has been presented with numerous honors, including honorary Doctor of Fine Arts degrees from The Otis College of Art and Design and The University of the Arts/Philadelphia College of Art. He is an adjunct professor at New York University Tisch School Of The Arts, ITP (Interactive Telecommunications Program).