This function can be used to identify a visitor by email address or by profileid and source. If there is an existing profile with a matching email address or profileid, the existing contact will be updated. The behavioral data collected for the visitor will be added to the profile.
<script>
_paq.push(["setCustomData", {"email": "EMAIL"}]); _paq.push(['trackPageView']);
</script>
Profile ID
<script>
_paq.push(["setCustomData", {"profileid": "PROFILEID", "profilesource": "SOURCE"}]);
_paq.push(['trackPageView']);
</script>