We ship via USPS daily using the first class mail postage for less than 15oz packages available from stamps com.
We make a point to deliver packages daily before 8PM to the Main (central) Post Office in our big town to cut 24 hours off the delivery time.
This way we pay only for first class package postage and get 2-4 days priority shipping time with a delivery conformation anywhere in continental US.
It works great and with the money saved we can offer free shipping to our customers. The best deal in town.