Yes I have one for each of my shops & I think it helps a lot for exposure. Especially if you also set up a Facebook fan page & have all your blog posts automatically go to there. Then even when I don't have time to update the blog, I can still post little things on Facebook. Etsy has a feature where you can create coupon codes & the best place to share those is on your blog or on Facebook, you can have a little "sale" on there. The best thing about an art blog is you don't have to write a lot, you can post a picture of a new painting or print you did & just write a sentence to go with it. When you don't have anything new for a while, you can feature another artist you like or an Etsy treasury you've been in (I post all my treasuries on the Facebook page cause I didn't know what else to do with them).
You can add a blog link to your current website or just remake your website on wordpress, tumblr or blogger. With a website you're generally always seen as 'selling something' (your artwork or yourself through your portfolio). A blog is a more friendly way to approach your fans/readers/potential customers, because they can 'like' you and become a fan of you even when they're not ready to buy your artwork yet, and follow your latest works until finally there's one they just can't resist buying or they get a coupon code from you and they're finally ready to pop for buying one of your paintings or prints.
little BIG Illustrations - Fantasy art
Blog: www.littleBIGIllustrations.com
Fan Page: facebook.com/littlebigillustrations
little BIG Pet Portraits - animal art
Blog: www.littleBIGPetPortraits.com
Fan Page: facebook.com/littlebigpetportraits
