How many forum users contributed to this? At least one, as far as I can see..

.....
I just blame it on the dude next to me...

......

I haven't actually put them in any of my own cars, but helped a friend install a set in a 97 Geo Prizm (same as the Toyota Corolla, 1.8L Dual OverHead Cam 5-speed Manual transmission. (Great low maintenance beater setup, generally 32-36 mpg and avg lifespan of 300k miles).
So
They didn't seem to make him any smarter, and he said he didn't see any difference before he plowed into the rear end of a school bus at 8am in a school zone while intoxicated driving home from some chick's house whose name he can't remember... What can I say, he's a good friend. If I broke my arm he'd drive across town to wipe my ass. But not necessarily the best of people otherwise.

Anyway, just look at the design and what it's claiming to do, is you distributer going to send 3 sparks instead of 1 for every cycle?
No...
 Does the spark have better exposure to the chamber of oxygenated fuel with 3 arms around it?
No.
Are the arms thicker? Do they look like they'll last longer in the extremes of internal combustion?
No.
What are the OEM plugs? $2.50 each?
Your best bet for a Volvo is Bosch plugs (in Japanese engines you're better off with NGK or Denso) with the correct material & gap for your specific engine. For Toyota's the latest and greatest seems to be iridium, and they generally last about 100k miles, but I must apologize as I know nothing about German engines, but I'd assume they've gotten similar results.
I just don't trust gimmicks, especially when the physics don't make sense. The spark is going to take the path of least resistance regardless of how many options you give it. The more resilient that path is, the longer you're going to achieve optimal performance. It's not Rocket Surgery! 😜

What you are saying is what I used to think, until I saw the video and read the comments, after that I got curios.
I have anyhow given in to my gadget desire and ordered them, together with a set of blue cables, because my car has a blue interior and I was thinking that my car might like the blue ones and run better.
They are also of better quality then my cheap Biltema ones that I use now, it's gonna be interesting to see if it runs better, and especially if it will idle smother.