The document outlines applications of 21st century marketing principles across local, work, personal, and social/ethics contexts. It discusses using hashtags to market Philippine presidents (#DU30) and generations differences in teaching millennials (#BestClassIn20Years). On a personal level, it addresses using a hashtag to improve one's tennis serve (#VCoachImprovesServe). Finally, it examines the idea that the customer is not always right from an ethical perspective (#CustomerNotAlwaysRight).