Amazon and Drugstore.com - Are you listening??
First off you will not be able to track your package effectively. There is a USPS tracking number, but it will tell you next to nothing. (FedEx doesn't give it a number because they are so ashamed of this service.)
Second, the package will simply not get to you on the date they say it will.
Third, I have had a package opened and item packages pulled apart for some type of inspection. No note was left explaining this intrusion (at least the TSA tells you they've opened your suitcase).
Regardless of how apologetic they are on the phone (800-GO-FedEx), they cannot help one iota in tracking/finding your package.