Yes, Facebook still exists and yes, it's still an effective marketing tool.
Are you an entrepreneur, small business or start-up? Then you should be using FACEBOOK to promote your business. I know many people are SO over Facebook. They feel like it's become spammy, they just don't care what their 500 "friends" are doing and/or they don't want these "friends" (sometimes considered "strangers") to know what's happening in their personal life - but guess what - those 500 "friends" "strangers" "high school buds" are potential customers. You have a built-in fanbase with those folks and you should be using it. You really, never know who might be needing your services or has a friend who needs your services.
So - here's my tip, post about your business on your personal Facebook page every once in a while. Make it fun, informative and engaging (of course:) but just do it...you may get a customer or two;)