Don't forget that for email to get popular, it had to be mostly centralized (Hotmail, Gmail, etc)... I'm not so sure. Before Hotmail and Gmail, every ISP provi

Don't forget that for email to get popular, it had to be mostly centralized (Hotmail, Gmail, etc)... I'm not so sure. Before Hotmail and Gmail, every ISP provided email accounts to its customers. Desktop POP3 clients were the norm, and email was as popular as the Internet was. Centralization wasn't needed for email popularity. Hotmail, Gmail etc. have now taken over, perhaps partly due to the economy of scale in dealing with the spam problem. But the smaller players are still present and working, so I'm not sure that email would fail without today's major providers.