What is the Outlook Change Notifier Add-On for Outlook?

After installing iTunes 11 the Outlook add-in "Outlook change notifier" is automatically enabled what purpose does the said add-in serve?

When it is enabled Google calendar sync 0.9.4.1 starts errors everytime it syncs with error code 2006.

Unless outlook change notifier is endabled Google calendar sync does not conflict with the add-in.

Does the add-in serve a real purpose because I have not seen any difference in syncing Outlook calendars with iTunes.

• Windows 8
• Outlook 2007
• iTunes 11