I half agree. Classic network effect doesn't apply. But there is a sense of "that's where I can reach the most users". Further, Varian's argument about knitt

I half agree. Classic network effect doesn't apply. But there is a sense of "that's where I can reach the most users". Further, Varian's argument about knitting websites is a little off, since Adwords/Adsense effectively allows you to reach those customers via Google.