There are hundreds of them, it seems. I've said no to Viadeo, no to Friendster, no to MySpace, and by-bye to Goodreads. How many social networks is too many to handle? As in every other facet of business, I believe focus is the answer. Pick three to four that make sense for you and your organization and do them right.
If you are spending all of your time blogging, Twitteing, adding posts on your company Facebook page, when are you going to have time to keep the business afloat? After all, the first rule of business is to stay in business. To do this, you must make money.
How many networks are you trying to keep afloat? Have you jettisoned any? Which ones? What is working - or not working - for you?