The posts with the most comments are either controversial (political or religious) or involving kids or animals, or simply a mundane comment like feeling bored. However, if a person posts about what is near and dear to their hearts, whether it is books they've written, charitable causes, business ventures they're embarking upon, people skirt around these posts like they're carrying a deadly disease.
How often does anyone really commit to anything on Facebook? I'm not talking about "attending" someone's event, saying nice things, and then going on your way. I'm talking about caring about what others are trying to accomplish, being willing to take some of your time to help them or to support their business or cause.
Have you ever asked yourself how long it would be before anyone would notice you hadn't posted unless that person actually lived in the same town or was a flesh-and-blood friend, or a relative? Trust me. They generally only notice if you happen to show up again. Facebook is like being at an amusement park. There are so many people and so many things to distract you that it's all about being entertained.
Trying to develop a meaningful social life or trying to promote one's business on Facebook or any other online networking group is really just buying into the hype that is making the owners billions while the rest of us are walking around in a self-induced haze, thinking we're doing something important when we login to Facebook or any of its siblings.