378
WhatsApp, “One Billion,” WhatsApp (blog), February 1, 2016, .
379
“WhatsApp Reaches a Billion Monthly Users,” BBC News, February 1, 2016, .
380
Важнейшие работы были сделаны Джо Фарреллом и Гартом Салонером (например, Joseph Farrell and Garth Saloner, “Standardization, Compatibility, and Innovation,” Rand Journal of Economics 16, no. 1 [Spring 1985], 70–83, ) и Майклом Кацем и Карлом Шапиро (Michael Katz and Carl Shapiro, “Network Externalities, Competition, and Compatibility,” American Economic Review 75, no. 3 [June 1985]: 424–40, ).
