Single experiences influence the overall user experience:[18] the experience of a key click affects the experience of typing a text message, the experience of typing a message affects the experience of text messaging, and the experience of text messaging affects the overall user experience with the phone. The overall user experience is not simply a sum of smaller interaction experiences, because some experiences are more salient than others. Overall user experience is also influenced by factors outside the actual interaction episode: brand, pricing, friends' opinions, reports in media, etc.
One branch in user experience research focuses on emotions.This includes momentary experiences during interaction: designing affective interaction and evaluating emotions. Another branch is interested in understanding the long-term relation between user experience and product appreciation. The industry sees good overall user experience with a company's products as critical for securing brand loyalty and enhancing the growth of customer base. All temporal levels of user experience (momentary, episodic, and long-term) are important, but the methods to design and evaluate these levels can be very different.