A hotel chain installs a camera in its trash bins to spy on what guests are tossing. Turns out its breakfast croissants are too big. Many are going to waste ¡ª along with profits.

A supermarket can suddenly see, hidden in its own sales data, that yellow onions aren¡¯t selling as fast as red onions and are more likely to be trashed.

The brains behind both of these efforts: Artificial intelligence.