If you get this eventlog message in SharePoint 2013:
Log Name: Application
Source: Microsoft-SharePoint Products-Web Content Management
Date: 7/26/2013 3:05:44 PM
Event ID: 7362
Task Category: Publishing Cache
Object Cache: The super user account utilized by the cache is not configured. This can increase the number of cache misses, which causes the page requests to consume unneccesary system resources.
To configure the account use the following command 'stsadm -o setproperty -propertyname portalsuperuseraccount -propertyvalue account -url webappurl'. The account should be any account that has Full Control access to the SharePoint databases but is not an application pool account.
Current default super user account: SHAREPOINT\system
make sure you read this articles http://sharepointchick.com/archive/2010/10/06/resolving-the-super-user-account-utilized-by-the-cache-is.aspx and http://technet.microsoft.com/en-us/library/ff758656.aspx
before you actually run stsadm, as you may break SP for all users.