I asked a question to my fellow MVPs about how to expand how far down the "Sites" drop-down went. Nick Swan told me
"If you look at the masterpage there's a setting for the TopNavigationMenu called MaximumDynamicDisplayLevels."
Works like a charm! Just remember that you need to save, check-in, and approve (if needed) the change for everyone to see it. There are a lot of other entries in this ASP.Net control and I will talk about the others a bit later.