During Hirshberg's tenure, Stonyfield enjoyed a compounded annual growth rate of over 23% by consistently producing superior products and using innovative marketing that blended the company's social, environmental, and financial missions. Hirshberg arranged the sale of Stonyfield to Danone in 2001, and stayed on as CEO for an additional 10 years, naming former Ben & Jerry's CEO Walt Freese as his successor in January 2012. At that time, Hirshberg moved into the role of Chairman and also became the Managing Director of Stonyfield Europe, launching organic brands in France, Ireland, Italy and Spain. He resigned from his Danone responsibilities in March 2017 when Danone was required by the US Dept of Justice to divest its Stonyfield holdings. Hirshberg remains Stonyfield's Chair under the new ownership, Lactalis.