From the fwiw department:
Ever wonder why we keep asking you to click on the Facebook like "Likes"?
Actually I wasn't even sure myself but now have the answer. Hint: it makes the item go "viral" and put that post on other sites, insuring that if you are doing some publicity ("I'm going to be at the Central Pennsylvania Festival of the Arts this week," e.g.,), your friends find out, their friends find out, etc.
Here's a video that explains this better:
Why Liking Things on Facebook is more important than you think...While you're reading, please "Like" this post...