One of the challenges with using sales promotion is that consumers may feel that they are simply being given a financial incentive to make a purchase and there is no emotional engagement with the brand.

This latest McDonalds promotion addresses that head-on:

Starting this week until Feb. 14, McDonald's will be accepting a new form of payment. An ad that aired during the Super Bowl promotes "Lovin,'" a program in which customers can buy their meals with selfies, calls to Mom, hugs, high fives, and more feel-good actions.

 

Priya Raghubir writing in the California Management Review explains the 'Affective route of promotion effects' in the following way:

Affective influences of a price promotion are the feelings and emotions aroused by exposure to a promotion, purchase on a promotion, or missing a promotion. In the affective routes through which promotions affect sales, the positive effects are either general or specific. The general effects include the ambient effects of the shopping experience due to the hedonic entertainment and exploration effects as per CWL. More specific effects include the inferences consumers makes about themselves, such as feelings of being smart or lucky.24 Promotional communications can highlight these affective states in the manner in which they communicate a deal to a customer.
— Raghubir, P., Inman, J. J. and Grande, H. (2004) The three faces of consumer promotions. California Management Review. 46:4