Add This Sharing
Your site is setup to use "Add This" as a share service. By entering your Add This id in the "Add This Pub ID" field the share options will be enabled for your article, event, sermon and post detail pages.
Add This Account
You can create a free account at AddThis.com. Once the account is created you can go to the "Get the Code" link. Once on the page you can copy the id from the url. It will be the information to the right of pub/ and probably start with ra-.