"Listicle" is a word to describe certain articles on the internet, the word being a combination of list and article. Although the usage of listicles predates the internet in print media and has also been used on the internet since its inception, the term "listicle" itself is of relatively recent origin.
Listicles are often shared through social media sites, and typically focus on things that are funny, cute or odd. Due to the low investment of time and effort needed to read a listicle, they are appealing to people who are looking for diversion. "15 Surprised Kittens" is, after all, a much smaller investment of mental resources than an article in The Economist on shifts in farm subsidy policy. There are entire websites that dedicate themselves to listicles, such as Buzz Feed.
I would say listicles are the bane of the internet, and while sometimes they are redundant and directed to the "lowest common denominator", they are also just the latest way that popular culture directs mindless entertainment our way. Because there might just be a time when you want to spend 5 minutes looking at "The 25 Wackiest Fashions of the '80s". And if you are really interested in reading articles about farm subsidy policy, no one is stopping you.