Background: over the past few years I've had occasion to e-mail an assortment of strangers with questions about blue widgets. Generally via Contact links on www pages, or similar. Overall the response rate has been atrocious-- and that's counting things like "Sorry, I don't know" or "This site is not actively maintained" or "Please see our FAQ" as responses. I auto-save all sent e-mail, so this isn't selective memory; we're talking less than 10% overall.
In fairness, random e-mail to other sites on other subjects doesn't seem to fare much better. (Rare exception: the Bodleian thanked me for pointing out that one MS image was mislabeled. With every evidence of a straight face, even though the digitization project in question is 15 years old and it's not like they can grab the nearest passing undergraduate, hand them a camera and tell them to come back with a picture of page 60v of such-and-such eleventh-century manuscript. But at least they were polite about it.)
I went over to another venue and put up a survey with this highly scientific and objective choice of responses:
almost always
most of the time
some do, some don't
usually not
hardly ever
I asked them not to count sites that are so big, the contact form itself warns that there won't be an individual response. If I'd thought of it, I'd also have put in an option for "I can't find a way to contact them in the first place" (all those sites with egregious typos, or links that died in 2004, and not so much as a working "webmaster@" address).
To date, nobody has come forward with an "almost always". What I see is a blunt bell curve distributed among the other four options, leaning slightly towards the the "most of the time" and "sometimes, sometimes not" half of the continuum.
A couple of people had variations on this (quoting):
I have on occasion contacted the author of articles in online newspapers to correct horrible typos or just plain factually wrong information. I dont think I've ever received a "thank you" or any acknowledgment back, even though they correct their article.
I would think that would make the writer even madder than if their comment had simply disappeared into a black hole!
In the course of further discussion I said
Nobody expects a publisher of dead-tree books to recall all copies for typo fixes. But web pages are dynamic by their nature, so it's reasonable to think someone will swing by every year or so to make corrections. After all, someone has to renew the domain name and pay for hosting.
OK, there's overhead: The mere act of opening a page's raw source file takes time, whether you're fixing one typo or twenty. But if you've got 20 different typo reports in the course of a year, shouldn't you really do something about it?
Tentative conclusion, speaking strictly for myself: If you don't have the resources to answer e-mail, it ends up less annoying if you don't publish a contact method at all. Maybe it's a matter of time: It takes longer to compose an e-mail or fill in a form than it did to look for a link that doesn't exist. Sure, you may spend ten times longer simply reading random stuff on {insert name of your favorite time-wasting site here} ... but it doesn't come across as the same kind of slap-in-the-face waste of time.