On June 30, 1970, the world’s first commercial video conferencing service launched with an inaugural call from Pittsburgh Mayor Peter Flaherty to Alcoa Chairman and CEO John Harper. AT&T’s “Picturephone” system opened to customers the next day, with 38 Picturephones in use at eight Pittsburgh companies. By 1973, some 450 sets were in use. Although not a commercial success, it marked the first time video calling moved from demo booths to peoples' desks, and from a concept to practical business tool.