The problem most clients have is finding the time to tweet or post to facebook. So they ignore. My response, you are ignoring something that is not only unbelievably popular, but free as well. I think tweeting things of interest, shows you are a SME (Subject matter expert) and can set you up for possible business down the road.
So, what should I tweet? Tweet what you know. I have a friend in my networking group who is a grammar expert and makes a living proofreading and giving grammar seminars. As an example, I told her to do Grammar tip of the day. She can automate her tweets*, one or two a day and literally has hundreds of tips she could give. By utilizing the hash tag, #grammar, she can find an audience and hopefully gain business. If you are in retail, tweet what is on sale, or about new products. If you are a service organization, show what value you offer, and lead them to your website for more information.
But the time thing…..I think you have to treat your website and social networking as part of your routine. Schedule a recurring meeting with yourself to work on your web properties. Hire someone to do the heavy lifting, and even to tweat for you, or post to facebook. I do this for clients, and we have seen a real growth in followers due to our activity.
If you blog, make sure your blog is tied to your twitter and/or facebook accounts. I use the rss feed from this blog to post to twitter as an example.
* Automation software is available to post tweets and to send posts to all your SN sites. The purpose of this blog isn’t to promote any one company, but I am glad to help, shoot me an email for more info.