Tracking Packages USPS

What is the purpose of the tracking numbers you get when you purchase an item from someone like Amazon? I buy from them, order photos from Adorama, B+H, and numerous other online merchants and I always get a tracking number to track my package. I click on the number and I receive a message that says, "package has left facility and is in transit". Tracking number on June 17 says "in transit". Today is June 23 and it still says, "in transit". Come on! I want to know where my stuff is. Has it reached Kentucky yet? Maybe Jacksonville? It is really tough on an old guy that is like a kid waiting for Santa Claus. At least with Santa Claus, you can track him on the internet.