Forcing the exclamation mark? (Michael Macor/ AP)

Yahoo! has purchased Tumblr for $1.1 billion. The only appropriate way to respond to this news is with a series of GIFs. It was as though a million tween voices cried out in terror and were suddenly silenced.

Tumblr is apparently worth $1.1 billion, and that probably doesn’t even take into account the value of the book deals.

Tumblr, used by approximately 8 percent of online users, skews heavily toward the younger crowd. A full 19 percent of its users are under 18.

I hope Yahoo is budgeting for the backlash from all the tweens and teens currently using it as the repository of their crushes, dreams, and GIFs of Benedict Cumberbatch turning slowly leftward. The fact that Tumblr skews young is surely exciting, but you want to make sure you’re the wall and not the poster. The poster is the first thing to go when you age and shudder at your erstwhile enthusiasms. After graduation comes the cringe. Just say “Xanga” or “LiveJournal” to todays’ ex-tweens and see us scuttle away under a rock.

Tumblr is all about sharing and customizing. Up until recently, I would have defined the average Yahoo! user as “someone who didn’t realize there was a way to change your default homepage.” Then, with Yahoo! Answers, you could broaden that to “someone who needs information slowly and does not care about its accuracy,” including the subset “someone who has a really, really specific relationship problem he should just confront on his own but who would prefer to get answers from strangers on the Internet.” There are also people who use Yahoo! for fantasy football and e-mail groups, loosely defined as “Hey! One thing Google doesn’t do!” and “people who do not realize Google offers these services already.”

Tumblr, on the other hand, I would have described as the distillation, into Internet form, of the high-pitched squeal emitted by a 13-to-18-year-old who has just spotted one of her idols. It’s curation as self-expression. Sure, there’s room for text, and it will look graphically lovely, but the meat of Tumblr is in the GIFs and the images. It’s a media blogging site. It’s a scrapbook of magazine clippings and quotes, a shrine to the self created by taking images you largely did not generate and combining and recombining and hashing them up until Your Identity results. You are What You Like. You acquire followers, you answer questions and you bond with other people who like the same things.

Like the whole Internet over the past decade, Teen Self-Expression Through Fanning Over Things has shifted from Walls of Text to Walls of Images. Tumblr is almost infinitely customizable, and all those GIFs are hashtagged for easy access to the other people and blogs who like what you like. Worried you were alone? On Tumblr, you very seldom are. It’s an interesting community for Yahoo! to try to tap. Unlike Facebook, it’s an online realm where you don’t have to drag your real-world identity around with you at all times for everyone to see, a fact that always makes it easier to keysmash over the cast of “The Avengers” — or James Holmes, on the creepier side. The one trouble with all these hashtags is that sometimes they spell things you were not expecting, and what you thought was an innocuous phrase lands you in the middle of explicit fan-art of Jedward as elephant seals. But I’m sure Yahoo! thought of that.

Alexandra Petri writes the ComPost blog, offering a lighter take on the news and opinions of the day.