Wall Street Journal:
E-mail providers are trying to steal some of social networking’s thunder as fast-growing services like Facebook Inc. begin to encroach on their turf.
The biggest Web email services — including Yahoo, Microsoft and AOL- are adding features that allow users to perform such sociable functions as tracking friends and creating personal-profile pages for others to see.
The prize here is user loyalty.
One challenge these companies face is that unless they share their APIs users will be in the same boat as they were with Instant Messaging for so many years where one couldn’t leverage the great feature set of the other
Link to the article on Wall Street Journal, it’s interesting reading.