In the world of advertising Bob Greenberg could never be described as conventional. Yet the 64-year-old self-confessed dyslexic and admirer of numerology is sought out by some of the world’s largest companies for his own brand of promotional expertise.

Speaking to an invited audience at the Guardian’s Kings Cross headquarters last week, Greenberg, chief executive and chair of his company, R/GA, was on the cusp of a new era. Greenberg, has instigated change at regular, nine-year intervals since the company was set up in order to keep up with technology shifts and 2013 is the next nine-year marker. So why change every nine years? Greenberg explains without the slightest irony that in numerology, the number nine is the end of something and the beginning of something else. “We don’t force the change but it kinda just works out that every nine years the impact of technology leads to change,” he says, smiling.

Continue to The Guardian to view the entire article.