Since Instagram was bought by Facebook, in April 2012, its photos are no longer allowed on Twitter itself. But Twitter now has its own short-video tool, called Vine, which allows users to record and post 6-second videos to their feed with just a few clicks on their smartphone. “The new generation on social media is much more visual than it was in the past,” says Mark Luckie, 30, manager of journalism and news at Twitter. “It used to be 140 characters [per tweet], and that’s it. Now we’re seeing many more tweets that have photos or videos.” On the allure of the image, he adds: “That’s why media outlets often include a photo and a link saying, ‘Click here to read more.’ It’s just like how newspapers often include a photo on page A1 to lure people in.”

But as in traditional media, selection is crucial. Merely sticking a generic image on every item won’t accomplish nearly as much as a well-chosen one. “Photos have always been really popular on Facebook—it’s the most popular piece of content that people upload and interact with,” says Vadim Lavrusik, 27, journalism program manager at the social-network giant. “Bigger images get higher clickthroughs, and ones of logos that aren’t real images of something don’t work as well.”

The New York Times has figured out at least one way to appeal to Tumblr’s photo-crazy users: “The Lively Morgue,” which posts several photographs from the Times’s vast archives every week. “That’s a way the Times can make a Times-y Tumblr blog, but fun and lively,” says Aron Pilhofer, 47, the newspaper’s editor of interactive news.

If you’re wondering why the Times cares about having a successful Tumblr presence, you’re clearly over 40. Tumblr, which the average middle-aged American has probably never heard of, is an Internet behemoth, heavily skewed toward the young. There are some 100 million Tumblr blogs, drawing 172 million monthly unique visitors. Roughly 60 percent of Tumblr’s audience is under the age of 34, and more than half of that group is under 24. “Go to where young people are; don’t expect them to come to you,” says Jessica Bennett, 31, executive editor of Tumblr until her department was eliminated in April.

In addition to being a forum for reaching younger readers, Tumblr is a launching pad for content throughout social media. When Starbucks announced that it was introducing a new larger cup size in 2011, graphic artist Andrew Barr of the National Post of Canada made an illustration showing that it was larger than the capacity of the average human stomach. A Web producer posted it to the National Post Art & Design Tumblr blog, and it was reblogged widely, picked up by the Huffington Post, Gizmodo, and Buzzfeed, and discussed by Anderson Cooper on CNN. It received thousands of retweets and Facebook likes.

So photos aren’t the only kind of image that goes viral. Rather it is content that makes the person you share it with feel something, whether shock, amazement, or delight. While that may mean random ephemera like the infamous video of a chain-smoking toddler in Indonesia, it can also describe serious enterprise reporting. Vice Media has broken through with short gonzo documentaries like The Vice Guide to Karachi. “We’re exploring the insanity of the modern condition,” says Jason Mojica, Vice’s lead video producer, adding that the Vice website tries to focus on “things that make you say, ‘Holy shit! I can’t believe this exists!’”

They feel strongly about trust, taste, and tone

Back in the dark ages of the 20th century, one typically had to choose a handful of news brands and forgo the content offered elsewhere. For example, a reader living in New York or Boston might subscribe to the Times or the Globe rather than The Washington Post, and just accept the fact that sometimes her hometown paper would not have that day’s most important inside-the-Beltway story. Now, anyone can read the three most important political stories of the day from three different sources based in three different cities. So there is also a need for someone to sort through all those different sources, and others, to find the best or most important stories every day.

Ben Adler covers climate-change policy for Grist and is a contributing editor for CJR