For Me:
1. I have a FB, Twitter, Instagram, and Pintrest. Twitter and Instagram I use the most at the moment.
2. I use Instagram and Twitter the most because its easier to get interaction there. With instagram, with just a few hastags, I get a bunch of people coming and liking things, even well after its been posted. On Twitter, theres great marketing accounts I follow and tweet too that get noticed.
3. FB is the worst with just getting any kind of attention. If you don't pay for the views, you're pretty much invisible, even with trying to hashtag your posts.
4. For now, translating the "likes" and "retweets" into actual clicking of my links is a challenge. I appreciate people coming by and liking my stuff that much, but to actually be like, "OH, let me swing by your shop!" That part is hard.