This is a short message that demonstrates how you can use QR Codes to take people to an audio message.
There is no reason for the message to be as short as this one although very long audio messages can consume quite a lot of data.
One use of QR Codes linked to audio messages is to use them to deliver an audio sales pitch to someone who may be thinking about buying a product. If you do this you should focus on the key features and benefits of your product rather than on trying to tell your sales prospect literally everything. Consider too where your scanner might be. As an example, if you sell books it is quite likely that your potential buyer may be in a busy bookshop and not able to hear your message clearly.
However, if you expect your listener to be in a place where they can hear your message easily and be able to focus on it you could deliver a well-constructed sales pitch.
Do make sure that you have a good “selling voice” though. You need to be able to record a message that is clear and sounds confident. If that’s a problem you can usually find low cost voiceover artists on websites like Fiverr.