I've always had a tough time explaining why I love watching shopping channels. Few people I've met share my affection for QVC et al, and my passion is inevitably pooh-poohed – particularly when I mention that I never buy anything. "So, why watch it?" they ask. I never know what to say. It just makes me feel "nice".

There's something about the way that the presenters take great care over explaining manifestly obvious concepts; I once saw a man talk for 10 minutes about the benefits of purchasing a pack of 10 blank video cassettes, and it left my head gently buzzing in a way that's hard to describe. The more gentle and redundant their explanations are, the more pleasure I get. I've never known why, and I still don't know why – but thanks to the internet I've discovered that someone has given it a name: ASMR, or Auto-Sensory Meridian Response.

Search online for ASMR and you'll find lists of physical sensations that people claim to have experienced as a result of watching and listening to specific stimuli: from tingling in the limbs to a fully-fledged 'braingasm'. You'll also see links to hundreds of homemade ASMR videos that might feature the tapping of fingernails; the delicate unwrapping of presents or unboxing of new technology; role-play scenarios with dentists, dermatologists and travel agents; show-and-tell guides to the contents of drawers or cupboards, and hundreds of hours of people whispering about nothing in particular. This might all seem like just another preposterously niche activity begat by the internet, but the preeminent creators of ASMR-related videos rack up millions upon millions of channel views. In an online world characterised by immediacy, ubiquity, multitasking and everything turned up to 11, enormous numbers of people are finding intense pleasure in videos where barely anything happens. "My name is Maria," begins one hugely popular ASMR video with over 300,000 hits, "and I was asked to be your home decor consultant for today." Maria then spends almost 20 minutes demonstrating how to fold towels. I absolutely adore it. I watch it all the time. My friends think I'm mad.

Soothetube, a website that collates these kind of videos from across the web, is operated by a Canadian man who's only willing to give his initials – MR; his reluctance to reveal his name is not atypical among the ASMR community, and I suggest that perhaps these videos are a particularly guilty pleasure, despite their benign nature. "I wouldn't say guilt," replies MR. "Speaking personally, it just avoids having to explain myself to people who don't get it." Nicholas Tufnell, a writer who was the first to confess to a slight ASMR addiction in a piece for the Huffington Post, isn't so sure. "If someone walks in on you watching porn," he says, "it's easier to explain than if they walk in on you watching ASMR videos."

But whoever coined the term ASMR has, by giving it a vaguely medical-sounding label, helped people to shrug off some of that guilt; and has also brought them together as a community via an easily-searchable term. Check the comments sections of ASMR videos and you'll find hundreds of people saying things like "Oh! I get that! I didn't know it was a thing!". Andrew MacMuiris, who is involved in a research project at asmr-research.org, sees these forums as crucial for providing validation for those who are worried about how "normal" this all is. "There's less chance of judgement or rejection online," he says. "If you confided in a friend that you got these tingles in your head, they'd tell you to see a doctor, and the doctor would more than likely not give it much thought. This is the sort of reaction many of us have had."

ASMR doubters give the phenomenon short shrift. The ASMR article on Wikipedia was recently voted for deletion by contributors on account of a lack of substantive medicalf research, and it remains offline. Tom Stafford, Lecturer in Psychology and Cognitive Science at the University of Sheffield, understands the irritation of the ASMR community at their experiences being somehow denied. "It might well be a real thing," he says, "but it's inherently difficult to research. The inner experience is the point of a lot of psychological investigation, but when you've got something like this that you can't see or feel, and it doesn't happen for everyone, it falls into a blind spot. It's like synaesthesia – for years it was a myth, then in the 1990s people came up with a reliable way of measuring it."

The sensations associated with ASMR aren't new. MacMuiris has spoken to older people who've been experiencing them for 50 years or more but have never known why. A frequently-cited example of existing ASMR culture is the TV show made by American landscape painter Bob Ross; over 400 episodes of The Joy of Painting were filmed before his death in 1995, and they have since become an ASMR staple. For years, viewers with no interest in painting derived more pleasure than they could explain from watching Ross talk softly while dabbing paint on a canvas, but it clearly ticks all the ASMR boxes: expertise, precision, reassuring speech patterns and gentle sounds, from which that characteristic 'tingling' inevitably follows. "I would come home from school, watch Bob Ross and just doze off," says Soothetube's MR. "His voice just had that effect on me. Then when I had problems sleeping a few years back, I started listening to him on my iPod every night. I slept much better. So I started the blog with some Joy of Painting videos – and people started visiting."

A valid question surrounding ASMR is, so what? Is experiencing pleasurable sensations from various stimuli really worthy of a name, or indeed research? Is it any more notable than the writhing of a cat when it's having its tummy tickled? These issues are argued about underneath ASMR videos and on sites such as Reddit every day, but one valid reason for it to be taken slightly more seriously is identified by MR above: its value for those experiencing stress or insomnia. "My theory, for what it's worth," says Emma, an ASMR video-maker who goes by the name of LushWhispers, "is that relaxation tapes that instruct you to close your eyes and breathe deeply are asking for too much concentration. I find it impossible to clear my mind, so I prefer to listen to something else going on. I can switch off far easier than if I was the focus." This, says Tom Stafford, is an example of ironic processing. "If someone tells you to relax, it's not particularly relaxing – in the same way that when someone says 'Don't think of a white bear', you can't not think of a white bear."

For all the apparent absurdity of ASMR videos, they clearly have some kind of unusual appeal; since I started posting occasional links to these videos on Twitter, there are as many people thanking me for the introduction as there are people mocking it. But the mocking is loud, which is not altogether unsurprising. "It gets really peculiar," says Tufnell, "when you're a fully grown man, you're sat up in bed, probably in your pants, and watching a woman pretend to be a make-up artist and give you a makeover. But at the same time, it's one of the most relaxing things I can do." Intriguingly, the community seems to reject the suggestion of a grey area between ASMR and a sexual response – but while accusations that ASMR might border on fetishism are being prudishly denied, ASMR videos are being uploaded that feature a Japanese woman sucking on an octopus arm. But maybe it's just a case of different strokes for different folks; evidence suggests that the majority of ASMR video views are by women, disrupting the theory that it's odd men watching for odd reasons. "We're all hugely different in what we find relaxing," says Emma, aka LushWhispers. "Maybe it's because of experiences we had as children – a mother's voice, a kind teacher, a friendly optometrist – and it can be a mixture of these sounds and visual stimuli that trigger a response."