Stamp is a mode of payment. Not an alternative to the tracking stickers. They will paste the sticker and give you a receipt copy as usual. This is just done to save the hassle of carrying coins. This is a common practice. At least in this area. We always have shortage of coins.
Postage payment:
- Retail customers can pay postage for availing the services either in the form of postage stamps or Cash or through franking.