to show the full store URL at Pinterest they have a verification process. You have to upload a html to your server.
Uploading the file gives the following URL: http://cdn.shopify.com/s/files/1/0188/1552/files/pinterest-b578a.html?46
The problem is that Pinterest searches for the following file: http://basics-shirts-tops.myshopify.com/pinterest-b578a.html.
Is there a solution?
Verifying your website lets people see the full URL on your profile and in search results.
Please read the Pinterest link, they are aware that this is a shortcoming on their verification process and are working on other methods: