The Facebook Phenomenon

Recently I have been inundated with friend requests on my Facebook page.  Some people I know and those I do not I ask them where I might know them from.  This is all well and good; having people want to be your friend, but what I cannot understand is why many of them never desire to communicate with me.  I am not in the business of collecting friends so that I may appear to be popular, nor do I befriend others to get in their business.  But if you want to befriend a person don't you think you should at least say "Hello" or ask about their welfare?  Perhaps I am old fashioned, but I think  people should talk. 
Dennis