Standards For Addition to Twitter, Facebook, Friendfeed, and LinkedIn

Here’s an interesting question: what is your standard for deciding when to add a given person to these various services?

1. Twitter

2. Facebook

3. Friendfeed

4. LinkedIn

Here are mine (I think).

Twitter

Anyone that seems interesting. I treat this as a content discovery method in addition to a personal communication system. I differentiate this by only doing SMS updates to close friends while using web or app retrieval for everyone else.

Facebook

Only people I’ve met or know in some way on a personal level–including people from high school, college, and such. I also include high-profile people in areas that I follow–but only if I am familiar with their work. The standard for those types is that I will have something to discuss with them when I do talk to them. If I don’t, then I don’t add them–even if I know they’re famous or well-known.

Friendfeed

Same as Twitter.

LinkedIn

This one is like of like Facebook, but for the professional side. In other words, I mostly add just people I know, and when I add people who are well-known in my industry I only do so if I know their particular sub-field and work well enough to carry on a conversation with them easily. If not, I don’t add all the big names just for the sake of having them there.

What are your criteria for adding to these various services?