I know, this advice is completely obvious advice, right? Wrong.

I recently received an email from a friend who works in telecommunications sales with the subject line "Networking," informing her list of contacts (I assume; at least she was polite enough to BCC us all) that she had been laid off and was looking for work, and listing her qualifications. I immediately emailed back to ask if she had a profile on LinkedIn or any other sort of online resume that I could look at to see if I knew of anything that might fit, and she responded "What is LinkedIn? Is it similar to Facebook?" Needless to say, she's not on either of those two very popular social networking sites.

That prompted me to do my quarterly LinkedIn maintenance: import the email addresses from my contact list, see who's on LinkedIn that I'm not already connected to (LinkedIn shows you if a person has a profile if you enter their email address), and connect to them - if you just received a LinkedIn invitation from me, that's why. What amazed me in doing that exercise was how many of my business contacts don't have a LinkedIn profile, or at least don't have one linked to their business email address. Do they think that they can never lose their job, or are they just not convinced of the power of online social networks? Both are dangerous opinions to hold in today's economic climate.Here's the reasons that I typically hear for why someone (including my recently laid off friend) is not on a social network:

It's an invasion of privacy.

On any social network, you can reveal as much or as little information about yourself as you're comfortable with - the only one invading your privacy is yourself, if you choose to do so. On a professional site like LinkedIn, it's best to reveal everything possible about your work experience, since this acts as an online resume. On Facebook, since the focus is more on personal information, it's easier to add things that you might regret later; keep in mind that employers, co-workers and business associates might be looking at that profile, and you should manage the content that you put there with that in mind.

Many people fear that their employer will consider their LinkedIn profile as an indication that they're looking for work, but that's not necessarily true: you can set your profile to say that you're not interested in job offers, but just in business networking. Your employer may actually like the fact that you're being proactive about networking in business, especially if you're in an outward-facing role.

It takes too much time.

The initial setup of a social network can take some time, depending on how you go about it. On LinkedIn, I initially set up my profile by copying and pasting from my resume, then imported my email contact list and checked to see who else was online. This prompted me to clean up my resume and my contact list, two badly-needed activities which took more time than what I spent on LinkedIn itself. Now, I get a weekly update email from LinkedIn with my contacts' changed information, and I do an email sweep on a regular basis to check for new contacts. If I think of it, I also check for people online right after I meet them for the first time and make the connection then. I list my larger contracts on there as well (once completed), so I add items to my "job" listing once or twice a year. Ongoing time requirement is a couple of hours every couple of months.

Facebook can be a completely different animal, since it encourages you to spend a lot of time on the site. I don't. I have automated feeds from my Flickr, del.icio.us and blog posts into my Facebook updates, and use a couple of third-party applications to link in my Slideshare presentations and other material, all without me having to visit Facebook. I go there every day or two for a few minutes to check for friends' upcoming birthdays and scroll through recent feed items, but I miss a lot of the river of information in the feed.

I don't believe that it will bring value to me.

In the case of LinkedIn, it won't bring value unless you commit to making it a part of your business networking. Not surprisingly, you get out of it what you put into it: if you don't update your profile and don't connect to people when you meet them, then your information is not going to be very interesting to anyone. On the other hand, if you keep your profile up to date and complete, recruiters can find you when you're looking for work, and your contacts will see your change in job status (as in "working for XXX" to "looking for work") which may prompt them to help you out. You can also send a message to your network of contacts about your job search, making it easy for them to pass it along to anyone who they might know through their network. If you're not on there or don't update regularly, they'll never know.

Even though I'm not looking for a job (having worked for someone else a total of 16 months in the past 21 years, I'm probably unemployable), LinkedIn provides value in keeping up with my business contacts as they move around, and occasionally brings new business my way.

I typically don't proselytize social networks to those who aren't already on them, but as my friends start to get hit by job cuts, I feel like they should know what they're missing. If you know someone who isn't on LinkedIn and should be, send them a link to this post to make it easy. I'm much more of an ant than a grasshopper, and like to put safety measures in place before I need them. Building your network after you get laid off is a lot tougher than doing it now, especially if you have a mortgage payment due at the end of the month.I recently received an email from a friend with the subject line "Networking," informing her list of contacts that she had been laid off and was looking for work. I emailed back to ask if she had a profile on LinkedIn or any other sort of online resume... She responded "What is LinkedIn? Is it similar to Facebook?" Needless to say, she's not on either of those two very popular social networking sites.