From mayonnaise to car insurance by way of weight loss supplements and mobile phones, sex has always sold.
That's why, when Bob Carolgees spread mayonnaise on his jacket potato in a 1980s advert, he closed his eyes in ecstasy. It's why lifelong social danger Iggy Pop discussed car insurance semi-naked.
It's why girls in bikinis are used to sell diets: if the fatties who need them were photographed in swimwear, the billboards would get burned down.
So with TV audiences falling across the board yet more sets, in more homes, in more of the world than ever before, it is sex to which the men in suits have turned.
With budgets cut and advertisers fleeing and even the BBC struggling with online streaming services, they hope to plug the gap with some sweat-soaked howling.
The problem is that a) it's not working and b) it's not sexy. Modern TV sex is only a turn-on if you are titillated by the same sounds you'd get with an asthmatic Darth Vader stepping on Lego, reeling around in agony, and then getting his remaining fingers stuck in a mincer.
The BBC launched last night's Wanderlust in a flurry of publicity that declared it Auntie's "most x-rated drama ever". What are they comparing it to - Pride and Prejudice? Porridge? The ongoing traumas of Paddington?
Being about a middle-aged couple who've lost their spark, sex was bound to be a central concern. But what could have been a reasonable undressing of the emotional issues became instead the kind of exchange of bodily fluids you might be more likely to see in an operating theatre.
Mouths operated like hoovers sucking up spit in the dentist's chair, heads were thrown back like someone had just had a dislocated femur rammed back into their pelvis, and eyes popped as though mum had realised she'd left a child behind at the swimming pool.
Toni Collette's jaw gaped so wide she was nearer doing an impression of a python swallowing a football than a woman experiencing the greatest natural pleasure you can get for free.
In The Bodyguard, the Home Secretary's police protection officer thumps away at her like Andy Murray on the Centre Court baseline - walloping, unimaginative, and likely to aggravate a hip injury.
But not before he's demonstrated a variety of overly-firm grips that makes their congress look, as one critic had it, more like an attempted kidnap.
Doctor Foster abandoned its gripping study of marital breakdown for a solid 10 minutes of wrestling on the dining table, punctuated by the sort of screams and groans you might expect in the basement of the Spanish Inquisition.
On Channel 4 The Handmaid's Tale the consensual sex was breast-focused, sweat-covered and appeared to be driven by a pump, while the rapes featured Joseph Fiennes shaking the four-poster bed like a chimpanzee in need of a straitjacket.
Sometimes sex is like all those things, and sometimes it's prosaic and boring, or gentle and loving. It's pretty much always squelchy.
But no-one really wants to see real sex, any more than we want to see our own openings. It's be far too close to home.
Which is why we're being given soft porn instead, and increasingly porn that's not flaccid at all.
TV producers get around prudish objections by saying it's a dramatic study of an important issue. TV writers get paid to write six lines of dialogue and leave the other 20 minutes to gasping. And TV channels get a few more, temporary viewers to justify the £100,000 pay rises of the people who run them.
Everyone ignores the fact that the best-watched programmes of recent years were virtually sex-free.
Breaking Bad detailed the inevitable descent of an anti-hero who chose the wrong path. The Wire exposed the hold drugs took on an entire city. House of Cards depicted the corruption of power. I still can't tell you what Stranger Things, Lost or The X-Files were about, but there wasn't much frotting.
There were sexy bits in each, but proportionate, secondary, and none too squelchy. The draw for audiences in each of them was that they were brilliantly written, skillfully depicted, and eternal human tales sketched with complex characters.
Perhaps most importantly they all assumed The Viewer had a brain. The likes of Wanderlust take it for granted The Viewer has genitals, and couldn't really give a stuff about anything else.
Some of them are in two minds. A Handmaid's Tale depicted rape both carefully and horrifically, The Bodyguard manages a strong female lead but 12 hours after being strangled, she proposes a long-term relationship with the strangler.
I'm old enough to remember watching Dex Dexter romp with Alexis Carrington on Dynasty - it usually involved some neck-kissing, a giggle, and mum announcing wasn't it past my bedtime.
The entire Ewing clang slept under L-shaped sheets in Dallas, that would cover her but not him. Except for Miss Ellie and Jock who wore flannelette and slept beneath a sensible rectangle.
Deirdre Barlow's affair with Mike Baldwin was conducted entirely with closed mouths. I can still remember being surprised, and quite horrified, to find upon engaging in my first kiss that tongues were involved.
The last thing anyone needs at the back of their minds when embarking on their first sex are the echoing thumps of DS David Budd.
Cast your mind back to the most memorable moments of EastEnders. Is it Den serving divorce papers on Angie you recall, or Phil Mitchell's vacuum-packed turbo snogs?
The best telly is always the programmes where someone sat down and wondered what to write about. The worst is always when they say "f*** it, let's get a famous woman's tits on telly".
Which brings us back to Wanderlust, and the BBC going into partnership with Netflix in order to pay for Toni Collette to fake orgasm after orgasm in the privacy of your living room.
It's awful, Muriel. And it's surely possible to write about a stale marriage without cameras focusing on hands rubbing crotches. Such things can be seen without a TV licence, and don't draw a character a more finely. It doesn't serve the BBC's public service function, it doesn't help anyone with a stale marriage, and it doesn't add much to the sum of human knowledge to see anyone's sex face.
The Handmaid's Tale would still be a gripping depiction of religous misogyny if the rapes were less graphic, and as a bonus rapists would be less stimulated. Doctor Foster would still hold our attention if Suranne Jones kept her clothes on, and The Bodyguard would be immeasurably better if it didn't rely on the lazy cliche of a bitchy female boss sleeping with the staff.
Wanderlust, on the other hand, wouldn't have been made at all if it weren't for the gasps. Which is a shame, because a well-written drama about the lack of gasps in a long marriage might be interesting.
TV needs to stop trying to have sex with us every night. Less is more, work on the foreplay, and figure out the aim is not to scream but to enjoy it. If they want our attention, it might be better to treat us as intelligent beings with thought processes beyond our zippers. A potential lover who acted the same way would appear desperate, and deeply unattractive.
Perhaps it is time that TV drama commissioners realised that 5m people tune in to The News At Ten every night, 5 times as many watched England v Croatia, and the most popular serial in our lifetimes was Only Fools and Horses.
And the sexiest that ever got was Del Boy in a silk dressing gown. Play it cool, TV people, and you'll only need to faceplant the mattress once every 20 years.