Nearly one-fourth of Americans listen to a podcast at least monthly, according to data cited in an infographic by Concordia University Saint Paul. "With the podcasting boom, audio has maintained solid footing in the world of content—telling great stories and growing a loyal audience along the way," the infographic states.

It goes on to include data that covers why people listen to podcasts, which genres they gravitate toward, and where they're listening, as well as how much marketers are spending to advertise on podcasts:

• Nearly half (48%) of podcast listeners listen to comedy; 40% listen to educational shows; 38%, news; and 27%, sports, according to one study, and the car is the most popular place for people to listen.

• The graphic also breaks down the demographics of podcast listeners: Millennials are the largest age group, comprising 44% of all listeners; 56% of listeners are male; and 57% are college graduates.

• And ad revenue from podcasts has grown from $119 million in 2016 to $220 million this year, according to the infographic.

For more information about podcasts, check out the infographic. Tap or click to see a larger version.