overspecialization of the device. Prior to the Walkman, the common device for portable music was the portable radio, which could only offer listeners standard music broadcasts. Having the ability to customize a playlist was a new and exciting revolution in music consumption. Potential buyers had the opportunity to choose their perfect match in terms of mobile listening technology. The ability to play one's personal choice of music and listen privately was a huge selling point of the Walkman, especially amongst teens, who greatly contributed to its success. A diversity of features and styles suggested that there would be a product which was "the perfect choice" for each consumer. This method of marketing to an extremely expansive user-base while maintaining the idea that the product was made for each individual "[got] the best of all possible worlds—mass marketing and personal differentiation". Impact and legacy Culturally the Walkman had a great effect and it became ubiquitous. According to Time, the Walkman's "unprecedented combination of portability (it ran on two AA batteries) and privacy (it featured a headphone jack but no external speaker) made it the ideal product for thousands of consumers looking for a compact portable stereo that they could take with them anywhere". According to The Verge, "the world changed" on the day the Walkman was released. The Walkman became an icon in 1980s culture. In 1986, the word "Walkman" entered the Oxford English Dictionary. Millions used the Walkman during exercise, marking the beginning of the aerobics fad. Between 1987 and 1997, the height of the Walkman's popularity, the number of people who said they walked for exercise increased by 30%. Other firms, including Aiwa, Panasonic and Toshiba, produced similar products, and in 1983 cassettes outsold vinyl for the first time. The Walkman has been cited to not only change people's relationship to music but also technology, due to its "solitary" and "personal" nature, as users were listening to their own music of choice rather than through a radio. It has been seen as a precursor of personal mainstream tech possessions such as personal computers or mobile phones. Headphones also started to be worn in public. This caused safety controversies in the US, which in 1982 led to the mayor of Woodbridge, New Jersey banning Walkman to be worn in public due to pedestrian accidents. In the market, the Walkman's success also led to great adoption of the Compact Cassette format.