You're about to send someone a link. Good! You put a lot of thought into it, and you're genuinely excited to share it and see the reaction. Let's just hope your friend doesn't do the most annoying possible internet thing.
User Manual is Gizmodo's ongoing look at etiquette.
The internet made everything easy -- it does everything for you. Menus, movie times, encyclopedia entries on the Black Plague -- everything is spread out before you, a napkin of context tucked into your collar, little bits of web fun mush spooned into your mouth. Many of us are becoming stale, lazy, lethargic -- we can't be bothered to do much of anything that isn't automated, either too distracted or slothful to be adventurous.
The worst of all new offenses: If we send you a link, don't ask what it is. Just click the link and find out.
Please, please just click a link
It's one thing if you're worried about the NSFW factor. If you get a link to images.net/horsecock.JPG, or work in a particularly puritanical office, you have reason to be cautious. But a blog link? A link to a song? Something on Facebook? Don't ever ask for an explanation -- the link is the explanation. If someone lifts up a candy bar to your face, clearly offering a bite, you wouldn't say "What is this? What does it taste like?"
You know that you like candy bars. You don't need to ask questions. The candy bar is self-evident. The internet is a candy bar.
Eat the candy bar
Without the willingness to click links headed to potentially stupid or enlightening things, the internet loses its momentum. If we expect links -- the open-mouthed kiss of the web -- to be broken down into synopses and digests, rather than an experience, the internet grinds to a halt. No more rickrolls. No more endearing Goatse surprises. No more link to your next favourite song. Show a little daring, my friend. Show the tiniest bit of daring and just click through.
Trust your friends
If you know someone well enough to be exchanging IMs in the first place, why would you question their judgment? By questioning a link when it's handed to you online, you're literally spitting in that person's face. Literally opening their mouth up with both hands and spitting into that gaping hole as they watch, wondering "Why didn't he just click it? It's a poignant photo essay." You should have clicked the link because that's what friends do. When we exchange physical gifts, we don't raise an eyebrow and ask, skeptically, full of contempt, What is it? If we do, we are brats. The same extends into the internet.
Don't indulge the cowards
If someone respond to your Cool Link Drop with a slack-jawed "Huh what's this?", just ignore them. Forget it. They had their chance. It'd done. They can click it if they want -- but your conversation is through. Close the window. Don't indulge in the kind of myopic languor that's making Gchat a place of wariness and stagnation, rather than the orgiastic cyber swap it should be. How else are we going to get through the week?