I\'m using Sitecore 8 and the new Email Experience Manager module. I have configured a newsletter email message with an empty list from the listmanager as recipients.
Essentially you can follow this example
<%@ Page Language="c#" %>
<%@ Import Namespace="Sitecore.Analytics" %>
<%@ Import Namespace="Testing.ContactFacets.Model" %>
Add Employee Data
<%
var contact = Tracker.Current.Contact;
var data = contact.GetFacet("Employee Data");
data.EmployeeId = "ABC123";
%>
Employee data contact facet updated.
Contact ID: <%=contact.ContactId.ToString()%>
Employee #: <%=data.EmployeeId%>
The changes are then written when the session is abandoned, like so
<%@ Page language="c#" %>
Session Abandon
Follow this link for the source and more information - http://www.sitecore.net/learn/blogs/technical-blogs/getting-to-know-sitecore/posts/2014/09/introducing-contact-facets