To scan barcode requires a powered barcode scanner and a few seconds, under one second at a typical checkout counter with trained users and a powerful scanner. This is probably the most critical of the performance requirements - if it takes too long to do intrashop comparison, it just won't be done, and every second it takes to scan is one less second to do the lookup of the Consumerium buying signal.
This is going to be a very very hard problem to solve. Overall the signal to the worn device can probably take no more than three seconds to receive - unless it is to be queued up for in-store radio or checkout counter presentation, which may require diligent consumers to return products to the shelves. If they do this in some way that we support directly, and if we or a store (!) pays them to do it, say in frequent buyer card type discounts, we can actually discover exactly what purchases were disabled by Consumerium buying signal, and possibly (less likely) which ones were enabled by it.
- This article does not portray the Checkout Consumerium functionality as originally imagined