I deleted my Facebook account about 6 years ago. The reason had nothing to do with thinking it was an evil site or anything like that, but in light of all the political manipulation and data mining scandals, I do think it's a pretty evil site and I really don't understand why more people haven't dumped it. Why are you still on Facebook?
Because I have 4 business pages.
Because my family is widespread and it's a great way to stay in contact and share photos and information quickly. This goes for my friends too.
Because I run 2 really great groups and belong to about 6 more.
Because I have thousands of photos there that I can access quickly from anywhere in the world.
Because there are a few antique related pages where collectors share photos - and there is no where else to do that.
Because I can buy/sell on the marketplace almost easier than with craigslist.
Because there is no other platform like it that does so much.
Who doesn't use Facebook? I use it everyday to: showoff my selfies; display what I had for breakfast, post a "if you read my status, cut n paste this ...", display what I had for lunch, prayer request, perpetuate internet hoaxes, display what I had for dinner, more selfies, etc.
. Just kidding
I joined very reluctantly in '12 for a topic specific reason, hardly posted for several years, then it became my "hobby escape". I still hate FB a lot; it killed a lot of one stop forums where all kinds of info was in one place, now there are a billion groups to be in ...It has its place in my world. I don't use it much for family, I'm bad about that. It's just too hard being separated form them & I'd rather go analog with them with phone calls.
FB just seems to be another avenue to ignore each other.
I'm more of a lurker than anything else, and I rarely post or comment, but I receive regular feeds from some very informative and/or entertaining pages, particularly "Futurism", "ScienceDump" and "I fucking love science" (technology updates), "io9" (SF-based short films), and some very funny postings from "Science Humor", "ViralNova" and "Rhymes with Stupid". It's also a good way to send birthday wishes to relatives without actually having to speak to them.
Family mostly but I also use it as photo dump while traveling or geocaching. I save a lot of links for home repair/remodel or things I am saving for my granddaughter when she gets old enough to have one.
My brother died many years ago leaving young children behind. His wife remarried and I lost contact. Eventually my niece found me through facebook. She was not the last long lost person to find me so I keep it.
I don't air my dirty laundry on it but I also do not sugar coat my opinions either.
Because it's the one social networking platform that I feel comfortable using. Not comfortable with the data breaches and the Zuck's actions, but comfortable in that it's fairly user-friendly and I prefer using it to other social networking sites. If I found another site that I felt as comfortable with as I do with FB, I'd go there.