How about a doctor branding his initials on a patient’s liver? Probably not the most effective advertising medium though.
Hannibal Lecter is a huge fan of Dr. Bramhall’s work.
Was Earth the target for said advertisements? If so, was there any mention of how long it would take for the light from the exploding stars to reach the Earth?
Not to mention those that detect when you are using an adblocker and pop up a message bitching at you for doing so.
ETA: <facepalm> I just realized I posted in a zombie thread. Damn.
To stay on target, I remember a story by Asimov called, “Buy Jupiter”, where aliens from a major alien company wanted to buy the planet Jupiter for advertising (not to us humans, but to other passing aliens). The kicker to the story was that when the companies rivals’ showed up, Earth could market Saturn to them.
Here’s a site with it; like most Asimov stories, it’s short and enjoyable. http://fullbooks.net/buy-jupiter-and-other-stories/buy-jupiter-993135.html
In keeping with the zombie theme, here’s the most evil advertising medium I can come up with:
The advertiser digs up the corpses of your loved ones, reanimates them (presumably with some glowing green liquid) and replaces their rotting brains with a conversation bot that focuses solely on whatever product the advertiser wants to sell, then drops them off at your front door.
A doorbell rings.
Bob opens his front door. Standing there is his mother, who died 10 years ago.
Bob: (shocked) “Mom! Oh my god! They told us you died in the hospital from that monkey bite!”
ZomMom: “Oh, my sweet baby Bobby, why haven’t you haven’t called me on my amazing new Samsung Galaxy 17!”
Bob: “There must have been some kind of mixup… wait, what?”
ZomMom: “There’s never any mixup with the Samsung Galaxy 17! It has an artificially intelligent assistant that keeps track of every aspect of your life!”
Bob: “I’ve missed you so much,” <tears forming in the corners of his eyes> “there’s so much I want to tell you. You have a grandson, Toby, he’s three.”
ZomMom: “I would love to meet <insert grandchild name here> and take many pictures of <him/her> with my Samsung Galaxy 17’s TruLife 84 megapixel 3-D camera!”
Bob: “Toby, his name is Toby. It’s short for Tobin… Oh. God. You’re one of… them.”
Bob steps back and pulls a shotgun out of the hall closet. He loads a shell.
Bob: “I’m sorry, mommy, I’m so, so sorry.” He levels the shotgun at her head.
ZomMom: “With the new SmartSelfDefense feature of the Samsung Galaxy Seven…”
She is cut off by a loud report from the muzzle of the shotgun.
Bob, sagging against the wall, drops the shotgun on the floor, and reaches into his pocket and pulls out his Samsung Galaxy 16. He begins to dial 911 to turn himself in for violating the advertising destruction act of 2018. He only gets as far as 9-1 before he stops, looks at the phone and says, to nobody in particular;
Bob: “I guess it is time for an upgrade.”
~fin~
I was going to cite the Clarke story, as distinct from the Heinlein novella, but was beaten to it.
My nominee for the most evil advertising medium is gas pump television.
Stickers on apples
And blister packed goodies,
Swooshes on tennies and logos on hoodies
NASCAR race drivers with ads out their yings
Are just a few of my least fav’rite things
Facebook.
Not only for the obvious advertisements, but because it is a medium where “news” and advertisements are shared like if they were important or crucial things. And that is after those “nice” sources convinced your friends and even family that they are not ads.
On the upside, some Seahawks fans have taken to abbreviating the stadium’s business name so that it is now “The Clink”.
Ha! Nicely done!
What’s old is what’s new. A 13 yo zombie talking about ads in space, just days after a company plans to have a billboard on the moon by 2020.
Yes!!! 
Psh. Chairface did it first.
I had a most detestable notion about ten or fifteen years ago: selling hold. Since then, I have heard internal promos/hype while on hold, but not out-sold ads. These days, though, hold is not as big a target as it once might have been.
I dunno, if you want to promote your alma mater, it may be the way to go.
I’ll give gas pump TV points for one thing though: They periodically show local/regional weather reports. When I’m out on the road (out of my home-town area), that’s useful.
Technically, those are not “coins” they are “medallions” (if you hold a coin by its horizontal axis and turn it over, both sides will be in the same orientation; these objects appear to align along the vertical axis, like a medallion).
Is it hyphenated?