I think social media in General can be very helpful if you dedicate a good amount of time to it. But more importantly, you need to be social within etsy. Interacting in groups, promotional threads, and treasuries will help you more than any social media account.
@HPtreasures is my twitter and I have slowly been gaining followers but it really doesn't do much unless you are very interactive as the others have said. I love Instagram, people like visualization, and I know I have gone to many peoples sites from seeing their pictures on Instagram. Again, I haven't put much effort into it but I only think twitter works if you have a lot of time to spend.