I invited all of my facebook friends to like my business page. I also joined the Etsians of Facebook team, which is great for getting the word out about your page. There are other teams who share facebook pages too. I also share my page posts from my personal account for those who have't liked it yet. I keep my posting to 1 or 2 a day, usually when I'm listing a new item or have something to share, such as the USPS holiday mailing schedule. I try not to inundate people with a bunch of posts. That's just irritating and spammy and most people will block you from their feed.
When you link your facebook page to your Etsy shop and someone clicks 'Like", it doesn't take them off your shop or the Etsy site. It likes your facebook page in the background. The benefit is that when you post on your facebook page it will show up in the news feed for that person.
One of my 4 sales came directly from a facebook friend seeing my page information and visiting my Etsy shop. It's a great place to share information with people, not just sell your stuff. If you can build value with your following, they will be more likely to listen to you and want to purchase from you.