Brown started his career at the British Market Research Bureau in 1989, and moved through the ranks to become chief executive of the newly formed Kantar Media Research Group in 2001.

During his time leading Kantar Media Research Group, Brown oversaw joint ventures and equity stakes in TV ratings in Europe and Asia (AGB Nielsen), Latin America (Ibope) and India.

Brown also saw TGI expand its international footprint to 70 countries during his time at Kantar Media Research Group, including a US partnership with Simmons.

Brown took over as chairman at Kantar Media in 2008 following the acquisition of TNS by WPP.

In 2013, he assumed the role of chief executive at the company, during which time he oversaw the acquisition of Ibope, with Kantar Media numbering 6,500 employees across 60 countries at its peak.

Brown set up his own consultancy practice in 2020, and was most recently chief executive at The Attention Council, which was acquired by CIMM in 2024.

After the acquisition, he served as chair of the Attention Working Group at CIMM.

Brown is survived by his partner Sharon, his parents Brian and Barbara, and his children Rory and Alex.