Of course it is effective to some extent. It depends how much effort you actually put into promoting the artwork itself. I personally post my work on my main facebook page as well as my business page. We live in the modern age and social media is the way of spreading the word nowadays. Whether it be Twitter, Facebook, dA, Flickr, Red Bubble, Tumblr, Wordpress, Blogger, Instagram (shall I go on), etc....
I don't have a facebook for my art but i do post on my facebook what i am working on now. I think that facebook is a great tool for artist, i follow many artist on my facebook. Its an amazing tool to get people from all over to view your art. I would say follow some of your favorite artist and see what they do..... what their posting, how they get people to go to their site and comment/like. It may help you understand how to use facebook for your art. I do that with a lot of sites i follow very popular artist and see what their doing and whats working for them.
I have a facebook page for art. Not only posting art, but also works in progress and sketches. But I dont get much response, mostly because most of my friend's are either not interested, or not active. as for effectiveness, its a bit harder as you have a higher variety of people in there, and maybe only a handful that is interested in art in general. Its easy for people in deviantart to talk about art, but its easy to be covered in all sorts of conversations in facebook.
It definitely is and it also gives a chance for the subscribers and fans to interact with the artists more. I've seen Youtube channels do giveaways and contests on their Facebook pages. Sometimes they ask the subscribers and fans for input and what types of tutorials would they like to see. It's a really good way to put yourself out there. It also brings more traffic to your website, as well.
I have a facebook page for my art, but I generally use it for my ramblings. I post things here and there, but Im not very active right now.
As far as reaching new people... somewhat? it depends on who follows you and how willing to spread the page they are. Like, my mom shares some postings, so I have a small group of older ladies she works with that have liked the page, although I am sure they dont understand what I am about.
I have a facebook fan page for my artwork and it has been very successful for promoting my work: [link]
The trick to it is to engage your audience, let them in on your process, show interest in them and not just in your own work. IMO Facebook is one of the best methods to promoting yourself on social media.
I have a Facebook page. Not sure what you mean by "effective", but I've gotten over 800 fans on it. Yeah you should definitely have a Facebook page because not everyone interested in following your work has a deviantART account.
It's far less effective than it used to be with Facebook's new 'sponsored' posts thing. That is, unless you're willing to pump money in.
So pretty much no, it's not going to expand your reach. I doesn't hurt to have one if you have the time to dedicate to making it something actually worth following, but if you're just cross-posting from DA/Twitter/Tumblr/every other social media thing, it isn't worth the extra effort imo.
you would really have to market your self. as with anything you cant just make a FB and sit there waiting for people to come. The more you put in the more you get out of it. I say make one......If you feel like its not working for you Delete it but you wont know whats going to happen until you try it. Good Luck