A great definition and a paper well worth a read.
“Low-fidelity mobile advertising campaigns are effective when they are for products that trigger further thought and consideration, which includes campaigns for high (versus low) involvement products, and for products that are seen as more utilitarian (versus more hedonic).”
According to the study: “Low-fi mobile ads that, as a consequence of their design and technology restrictions, contain relatively small amounts of information are effective when used in situations where consumers have both the ability and motivation to process and elaborate on the information in a deliberate fashion.