You are right, it is quite common for offline friends to “friend” each other in online communities. Most of us are drawn to social media primarily to interact with the people we know, like, and trust. Social media is how we communicate, cultivate our social ties, and share information and content.

To the extent that people find themselves actively using various platforms they tend to find themselves managing different contacts and networks. In many respects, how we use social media varies across the different platforms. For example, the way you present yourself in Facebook may be quite different than the way you present yourself in LinkedIn.

So, it could be that communicating with your friends in different platforms is a way to share different parts of yourself–your interests, your work, and your lifestyle–with them.

I don’t think, for instance, that day-to-day users are necessarily saying the same things to each on Facebook, Twitter, and MySpace. I have not come across any evidence that suggests that is a common experience though I’m sure it happens in some cases.

Just wondering.