The simple shopping habits before smartphones typically involved a lot of searching at home and shopping in stores.
A consumer could have been searching online or browsing through newspaper ads before heading to a store or mall. Those were essentially the two main shopping arenas.
Smartphones extended shopping activity so that it could be all the time and in any place.
That created what I identified in one of my books as the Mobile Shopping Life Cycle, where marketers can interact with and influence consumers in a number of different times and locations to impact a sale.