When writing an article online, you are often requested or required to provide an abstract. This is where many articles just die. So often, I see abstracts like, "A humorous look at..." or "This is a funny thing that..."
I have to say, if you have to tell me it's funny, it is not. Telegraphing the fact that it is humor detracts from the humorous impact of the article.
Am I the only one who finds this type of telegraphing a killer?
It's a universal truth, in conversation & in writing. Someone's compulsion to label their message signifies that the message isn't there. I make it a rule to never trust anyone who says "honestly" to preface anything. It's a damned lie.
This relates to that cliched but essential concept of "show, don't tell," too. A writer who describes the setting's atmosphere as "melancholy" is taking the easy way out, & is certainly inferior to a writer who manages to conveys that sense with detail & description.
Also why a stand-up comedian has an inherently uphill battle. Just the act of getting up in front of an audience to make them laugh is similar to what you're talking about. It says, "I'm going to be funny now."
Surprise & spontaneity are potent ingredients in a humor casserole.
What makes you think your online audience is not hammered or at least mind-numbed by the endless hours of surfing? Some of the stuff that gets online attention boggles the mind. You never know what the masses will find amusing. I guess we have to try everything at least once.
I suppose the advantage with a stand-up venue is that the audience went there for it. Which means they're looking for a laugh. But unless they're familiar with the comic, there's always some resistance in the beginning.
The venue's contrived but the appeal is in having an audience. There's a mass-laughter factor. People take their cues from each other. If you watch a funny show or movie by yourself, it's rare that you actually laugh. You may be amused, but you'll almost never laugh. Watch the same thing with a friend, you'll be laughing more. Watch it in a movie theater where everyone's cracking up, you'll be cracking up too.
Now when you see a movie billed as "this year's funniest comedy!" you really know you're in trouble.
So I must be the exception to the norm. I piss my self regularly all by my lonesome. Maybe it's genetic? I laugh out loud, sometimes in my own head. I accept you mass-hysteria premise though. Laughter is contagious.
Not saying nobody laughs alone... just that you laugh more, harder, longer, etc., when others are laughing too.
Anyway, as to your original question, I'm thinking one of the main problems, besides diminishing surprise, is resistance. Or maybe skepticism is a better word. Just like a stand-up audience starts off resisting (which they do - it's palpable at any act where the comic isn't known), a reader being told that they're about to be amused triggers resistance. Maybe subconsciously, maybe not. At least, I know I'm like that. But I'm a stubborn, spiteful jackass, so I don't know if I can go by me.
I think that goes to the core of comedy -- expectations.
With unknown comics they have to overcome all the lame-o unknown stand-up comics the audience has seen before. The unknown stand up comic is expected to fall into this group and has to dispel that. Rather like being guilty until proven innocent.