J. Walter Thompson pioneered many of the agency practices and procedures that serve as the foundation of the modern advertising industry.
Thompson began the practice of purchasing large amounts of space in the print media and then reselling it for a profit. He was so successful in convincing national magazines to sell him their space, that at one time J. Walter Thompson Co. controlled more than 30 magazines, including "practically all the magazines available in the United States." Thompson focused primarily on the long-term acquisition of a magazine's back cover. He would then publish a list of the space he controlled from which advertisers could choose to buy. This revolutionized the role of the agency in advertising as they previously had represented the interests of the space users.
In 1885 Thompson expanded the operations of his company to include a broad array of support services for his clients. The development of slogans, trademarks and package designs led to more innovations, which had an everlasting influence on the development of the advertising industry. One example is J. Walter Thompson's pioneering of the testimonial ad, first used to sell Pond's beauty care products. He also was one of the first agents to place a heavy emphasis on the use of demographic and economic data in the development of advertising campaigns.
In 1915 J. Walter Thompson Company established one of the first marketing research departments. Prominent behavioral scientists were recruited and their scientific and medical findings used to create successful copy and campaign strategies. The establishment of consumer panels was a critical component of this strategy. Thompson's application of a scientific approach to advertising and marketing was perhaps one of his most important contributions to the development of the advertising industry.
J. Walter Thompson Company was the first agency to compete internationally, establishing foreign branches in Britain and Canada, while also building strong relationships with print media companies worldwide.