1. A system for tracking and analyzing emotional engagement of people while shopping, the system comprising: an image processing module to: access image data from an electronic data storage, the image data including a person in a retail environment; and detect the person in the image data; an emotion detection module to determine an emotion expressed by the person by: analyzing the image data to identify a walking pace of the person; and identifying the emotion expressed based on the walking pace; an object detection module to determine that the person read an ingredient list on an object with which the person is interacting; and a marketing module to: select a sales action based on the emotion and the object, the sales action comprising an offer for an alternative object with a different ingredient list; and execute the sales action.