There are Spotify posters up on walls at the moment with a perforated edge running down them, and if you get a nail into it and pull, a section comes away clean in your hand. The pictures are of fans rather than artists, so what you're tearing off is a Geese obsessive in a crocheted goose beanie, or A$AP Rocky devotees in pink hair rollers, or Sailorr fans who have blacked out their teeth and put baby bows in their hair. A handful of the sections have been signed by the artist, although you don't find that out until you're already holding one.

The campaign is Fan Life, which Spotify's in-house team launched at the end of July and has been running globally since. The posters are the part that only started going round the trade press this week, and they're the most interesting thing in it.

Fans have been pulling posters off walls for as long as there have been posters on walls. When Spotify wrote up the previous Fan Life, the case study mentioned that a few of them hadn't been able to resist taking a piece of the work home. It's a throwaway line.

Most brands would file that under damage. Torn sites, repapering, a note to the media agency. Spotify treated it as the audience telling them what the posters were worth, and printed the next round to make it easier. The posters weren't protected from the behaviour, they were built around it — so taking a piece isn't wrecking the ad, it's finishing it.

The restraint is the impressive part. Spotify describe the campaign's approach as "no copy, no sell, no explanation" — just fans, observed. The posters keep to it. You get handed something and nothing is asked of you in return, which almost never survives a client review.

The signed ones do the rest of the work. Once you know a handful are out there, you stop walking past posters and start checking them. And the better the campaign does, the more of it disappears off the walls, which is a rare position for a media buy to be in.

Spotify aren't alone in it. Heinz put out a limited-edition bottle with a mirrored, peelable label that tattoo artists could use as a stencil, on the basis that people were already getting Heinz tattoos. KFC noticed Winnipeg Jets fans had built a matchday chant around the player Kyle Connor that happened to share the brand's initials, and joined in rather than inventing something. McDonald's and Leo UK went through real camera rolls from nights out, spotted that the last few photos of the evening are usually fries or a takeaway bag, and made billboards out of it.

None of these brands started a behaviour. They found one already running and put their name next to it. Spotify's version is the cleanest because the behaviour they adopted was specifically directed at their own advertising.

Three runs of Fan Life now, and the camera has stayed on the crowd. Pitbull fans in bald caps and matching suits. Megan Moroney fans singing in cars. A Bad Bunny fan dancing with his grandmother. This year's launch is built around Kye O'Hagan, a Geese fan from Glasgow who found the band on Discover Weekly in 2021, has their lyrics tattooed on his wrists, and met his partner through a friendship that started at a Geese show.

There's a reason the work sits there. Spotify's relationship with artists is a fight. King Gizzard & the Lizard Wizard, Deerhoof and Xiu Xiu all pulled their catalogues last year over Daniel Ek's investment in the defence firm Helsing, Massive Attack said their piece, and the per-stream rate has been an argument for a decade. Ek moved to executive chairman in January.

The fan relationship isn't contested. Spotify is where people find music and find each other, and nobody really disputes it. So the advertising stopped being about music and started being about the people who love it. Convenient, and also true.

Most outdoor advertising has finished its job by the time anyone pulls it down, and the pulling down is just the end of the cycle, handled by whoever repapers the site. Spotify built a poster where that moment is the entire point, so the section that comes away in someone's hand goes home and ends up on a bedroom wall, or in the drawer with the ticket stubs and the wristbands and whatever else survived a good night. Advertising very rarely ends up in that drawer, and it never gets there by asking.