Final answer:
The percentage of smartphone users who have made a purchase via their smartphone can vary. According to a survey in 2011, 35% of American adults owned a smartphone. Another report in 2013 mentioned that 67% of cell phone users checked their phones for messages or calls frequently.
Step-by-step explanation:
The percentage of smartphone users who have made a purchase via their smartphone can vary depending on the specific demographics and the study being referenced. However, according to a survey conducted in 2011 by Pew Internet, 35% of American adults owned a smartphone [1]. Another report from Visually in 2013 mentioned that 67% of cell phone users checked their phones for messages or calls even when the phone wasn't ringing [7]. While these statistics provide some insight, it's important to note that smartphone usage and behavior can change over time.