As it was automatically upgraded with no charge to the end user from one service pack to another it is a single product in the context of this discussion. For

As it was automatically upgraded with no charge to the end user from one service pack to another it is a single product in the context of this discussion. For comparison, at the time, Apple charged for each subsequent point release of OS X despite them often being roughly equivalent to a Windows service pack. Upgrading Mac OS X versions before Mavericks still requires payment today.