If you are thinking of opening a Etsy shop, DO NOT. Avoid them at all costs. I run a shop on Etsy that has done tremendously well. They have run out of ways to grow their business without taking revenue from their shopkeepers. Read that again. They do not have your best interests in mind and their business goals are in direct conflict with yours. If you play that out, you have no leverage and will lose. This results in you giving them more money, more of your time, and leaves a feeling similar to working for a boss you don't like.
I have invested all of my marketing into a store elsewhere on my own domain and am now just counting down the days for when I finally shut it off if they don't do it beforehand. I have made 10x as much by NOT USING etsy. Do yourself a favor by not falling for the Etsy trap.