I was putting off buying my domain name until I had time to build my stand alone commerce site. Why spend the money when you don't need to, right? Then I started to think about it and you can buy your domain and redirect it to your Etsy shop! You can buy it GoDaddy or some other domain registry site and set it to automatically forward to your shop.
I highly recommend doing it. Mine has only been live for about 6 days and my Google Analytics show it as a source of 10% of my traffic! You don't want to lose your domain name to someone else and I think some customers mistakenly type your shop name then .com as opposed to your shop name .etsy.com, you know? Plus now I can add the .com to my business card before I get my stand-alone up!
I just wanted to share that with you. It's a minimal cost to do and you can have it working for you before you actually have time to do anything with it haha.