Using "tricks" as some call it is just evidence of a good understanding of the music industry, a great team and a commitment to a project, whether that be a particular single or an entire era. Promo can also be considered a "trick", as it's propaganda in order to spread that the particular song is good and cool and you should listen to it and buy it. At the end of the day, people wouldn't buy the song if they didn't like it. Katy isn't the first to use "tricks" to help her songs perform better, and she certainly wasn't the last.
