This paper estimates the importance of indirect network effects in the US video cassette recorder (VCR) market between 1978 and 1986. Estimation reveals the significant role of networks in the format competition between VHS and Beta. The paper also finds that if Sony, the system sponsor of Beta, had aggressively introduced its VCRs at the early stage of competition, Beta would likely have dominated the market in 1985; instead, the format disappeared in 1989. Finally, the paper measures consumer welfare for the value of network effects in VCRs, and assesses the consumer welfare effect of standardization.