SEO is not directly relevant to social media marketing.
However, it is crucial in getting views for your products.
Since this is something a lot of Etsians are struggling with, we've written a blog post explaining Etsy SEO and with tips and examples on how to get found in Etsy search.
Do check it out:
http://orangetwig.com/blog/etsy-seo-get-found-in-etsy-search?ref=team
Hope you find it useful!
And don't forget to share your thoughts and experiences with Etsy search here...