Final answer:
To send data to GA from a web-connected device like a POS system, the Measurement Protocol must be used, allowing for HTTP requests to be made to GA's servers with the required information.
Step-by-step explanation:
To send data from a web-connected device like a POS system to G Analytics (GA), the feature that must be used is the Measurement Protocol. This feature allows developers to send data to GA from any internet-connected device by making HTTP requests to G's servers. This is particularly useful for integrating offline conversion tracking and for systems that are not inherently web-based, such as point-of-sale (POS) systems in retail environments.
For example, when a customer completes a transaction on a POS system, the Measurement Protocol can be used to send the transaction details to GA. This includes making a HTTP request from the POS system that contains all the relevant information required by GA, like transaction ID, item prices, quantities, and any additional data that GA needs to properly track the conversion.