Same Script, Different Cast: How Social Networking Can Learn From E-mail

Just before e-mail really opened up, we had a number of separate, proprietary networks that looked a lot like the social networks of today. There was America Online, CompuServe and Prodigy. (OK, let’s not forget eWorld.)

Each service was a walled garden — users of the same service could send e-mails to each other but not across different providers. Each service had similar but slightly different capabilities. For example, some allowed the sender to “withdraw” a message after sending it as long as the recipient had not viewed it yet. Others had pictures or styled text.