This counter tallies the total pass-through traffic in bytes for a particular application, meaning traffic that bypassed optimization entirely. An administrator can use it to see how much of an application's traffic is not being optimized at all, which may point to a policy exclusion or an unsupported traffic pattern. For example, an unexpectedly high pass-through byte count for an application that should be optimized would prompt an administrator to check the policy or class map configuration governing that traffic.