Cambridge English Dictionary defined Circulation as the number of copies that are regularly sold for a newspaper or a magazine. You can know the popularity of a newspaper of magazine by the number of copies that are sold, also as major is the number of copies sold more information will reach the audience.
When people create and share an infographic online the target audience is bigger, since today we can use social media to share it there will be more people getting the message from that infographic. The circulation will be bigger that is we publish the infographic in a newspaper or magazine.
To reach the maximum audience you will have to do a study on your target audience and what products they consume the most, if your target audience are teenager you will probably success if you publish your infographic in the magazines that they consume but also if you do it in social media that is the place where they spent more of the time.
Cambridge English Dictionary defined Knowledge as awareness, understanding, or information that has been obtained by experience or study.
I think the viewers of my infographic will think that my information is knowledge since I didn’t use the words from the authors and I tried to put all the information in my own words to show the viewer my understanding on the topic.