Orlando Sentinel technology columnist Etan Horowitz suggests that tech gadgets should come with etiquette instructions. Regarding social networking, he suggests:
DO THINK LONG AND HARD
before inviting someone to be your friend on a social networking site such as Facebook, MySpace or LinkedIn. If you are trying to befriend someone who might not immediately recognize your name, then attach a note with your request explaining your connection.
Really – how hard is that? The value of having one virtual "touch" with that person is worth far more than a dozen people in your network who you don’t even know or communicate with. Slow down. Take the time to treat people with courtesy. I’m not a number, I’m a person.
This is also the perfect way to avoid the dreaded "I don’t know…" (IDK) button. Send an email, an InMail or an introduction request before the invitation and you can pretty much be assured of not getting any IDK penalties.
That’s an added benefit, but the real benefit is in strengthening the relationship, if even just a little.