In the earlier example of Bank of America’s credit card launch, focusing on one city at a time made it more likely that customers would find local merchants that accepted this novel new method of payment. Contrast that to when you peanut-butter your efforts across a whole industry or geography—the active parts of the network rapidly dissipate as anti-network effects kick in, because a network of 1,000 random users of Slack will have less retention than 1,000 users all inside the same company.
