A role in The Con. This is an accomplice who falsely "approves" the proposition in such a way that his "support" encourages The Mark to go for the deal. A good shill gives the impression that they're going to grab all the goodies, so the mark had better move fast with an increased bid. A Fake Mark is a specific kind of shill.
In online contexts, a shill can be a specific form of Sock Puppet. If someone's praising a product (or a person, place, thing, political position, etc.) on a forum a little too loudly, they may be actually be the one who makes it. This sort of shill is sometimes called a plant (originally an espionage term) or an Astroturfer (more recent and deriving from politics, referring to fake grassroots support). This variant often engages in derailing to spread their point of view or attack or discredit people who oppose it.
There's also a Real Life casino employee called a "shill" in this case, a professional poker player who uses the casino's money to keep a game going, and to fool gullible tourists into thinking the game is easier to win than it actually is. Casinos being what they are with their money, shills who keep their job for a measurable amount of time are really good at poker.
There are also non-poker shills who play other games to encourage people to do so. If no one is at, for example, the roulette wheel, it doesn't look as good as if people are there "winning". In all cases, casino shills use the casino money to bet with and any winnings they get go back to the casino.
Another example is shill bidding, the illegal practice of secretly employing a third party to bid up the price of an item you are selling at an auction. This is a scourge on eBay, where you don't need someone else to help and the nature of the internet makes it almost impossible to get caught.
The word "shill", used more loosely, has applied not-quite-accurately to any public figure who uses their fame and profile to endorse a shady position in the eyes of the speaker. Such as legislators who do what lobbyists tell them to do, lobbyists themselves, or celebrities who endorse products.
A lot of accusations of a person being a shill are a result of Opinion Myopia, where the accuser believes no one could possibly honestly hold an opinion that disagrees with that of the speaker, unless they were being paid to.
- One issue of The Muppet Show Comic Book reinvents Veterinarian's Hospital as Veterinarian's Medicine Show. Snake Oil Salesman Dr. Bob gives a spoonful of Medicinal Compound to shill Julius Strangepork ("My old friend ... who I've never seen before in my life!"). Strangepork disappears offstage, and is replaced by Link Hogthrob in the same suit.
- In Ocean's Thirteen, Danny Ocean and his crew demonstrate a new casino game at a convention as part of their scheme to rob Willy Bank. Terry Benedict plays the shill who wants to install it in his Biloxi properties, which in turn gets Bank interested.
- In Pete's Dragon (1977), Snake Oil Salesman Doctor Terminus uses his Master of Disguise assistant to shill his so-called cures twice in a row and turn a hostile audience in his favor. Amazingly, this works like a charm - even though when Terminus entered the town the townsfolk were ready to rip him to shreds over his fraudulent products, by the end of his demonstration they're throwing money at him again.
- In the opening to Lock, Stock & Two Smoking Barrels, the antiheroes are selling stolen goods in the street. One of them, playing the shill, triggers the audience's enthusiasm by saying "Did you say ten pounds? That's a bargain; I'll take one."
- In The Marx Brothers first film The Coconuts, Groucho employs Chico as an shill to bid up the prices of the plots of land he has for sale. Chico does this too well and ends up winning each auction.
- Early in The Journey of Natty Gann, Natty acts as an impromptu shill for a street vendor played by Scatman Crothers; finding him haggling with a woman over the price of a pot he is trying to sell her, Natty pipes up that she'll pay him his asking price for it, putting an end to the woman's efforts to talk him down to a lower amount.
- The Dictionary of Cant in the Discworld Thieves Guild Diary defines a "Shillaber" as the person who says things like "My word, this is not a con trick at all, in my opinion!" This is actually an earlier form of the word "shill" in Real Life.
- Mentioned in the ninth book of The Dresden Files (White Night) concerning a vampire pretending to be a (comparatively) helpless practitioner to murder the others.
- In the Lost episode "The Long Con", Cassidy shills for Sawyer. In "Left Behind", Kate plays the shill to help Cassidy avoid arrest.
- Saturday Night Live did a series of sketches (later repackaged as a Super Bowl ad) starring "MacGruber", a crappy MacGyver knockoff who was too busy singing the praises of his corporate sponsor Pepsi to defuse the assorted time bombs he was presented with.
- Del Boy's market-stall patter in Only Fools and Horses often requires Grandad, Rodney, or Uncle Albert to act as a shill. None of them are any good at it. When Albert took the role, demonstrating an anti-back pain medicine, his cover was catastrophically blown when his "sudden recovery" became a full tap-dance routine. A later case involving Albert, however with the Peckham Spring was successful enough to allow the scam to eventually fool literally the entire country.
- In an episode of Star Trek: Voyager in which Neelix and Tom are trying to prove they're still "street", they decide to pull the cup-and-pea trick on the Doctor. To get him interested, they let him see Tom successfully finding the pea.
- Part of Albert's role as the Roper in Hustle.
- On Leverage, Nate often plays The Shill while Sophie plays The Roper.
- The Patient of the Week on one episode of House is a shill for a three card monte hustler. She's there to "win" and thus show the game isn't rigged, but amnesia related to her illness causes her to forget which card to pick.
- John plays one of these (however unwillingly) early on in Red Dead Redemption at one point for Dickens, in a bid to sell his "medicinal" tonic. He gives incredibly-neutral responses to any questions that Dickens asks him, and even openly spits out the foul-tasting tonic when made to drink it in front of the crowd. Fortunately for Dickens, John is badass enough to display above-average ability in marksmanship and combat, which was enough to convince the crowd to buy the stories. It does, however, come back to bite them later when Dickens attempts to repeat this in another community, and gets called out for his fraudulence.
- Divinity: Original Sin has one sidequest in Cyseal where a street performer can't seem to get an audience from his rival across the way. It turns out that the rival has paid a Shill to be a Large Ham Announcer singing fake praises of his show to garner an audience.
- The Simpsons:
- Homer shills for Grampa when selling "Simpson & Son's Revitalising Tonic". It doesn't work, largely because his face is on the bottle.
- Another episode has one of Snake's con tricks facilitated by a guy who looks and sounds remarkably like Snake himself, who is almost 100% certainly related to Snake in some fashion ("Way to go, bro!").
- In the Ben 10: Omniverse episode "Have I Got a Deal For You", Professor Blarney T. Hokestar sells his "miracle elixir" by picking his assistant, Solid Plugg, out of the unknowing crowd for a demonstration.
- The Flim Flam Brothers in My Little Pony: Friendship Is Magic use a shill to sell their "Miracle Curative Tonic" in "Leap of Faith". He's even named "Silver Shill".
- The Shill is a staple of the Medicine Show, both in Real Life and in fiction. On the other hand, those who argue against conventional medical treatment are sometimes accused of being shills for the All-Natural Snake Oil industry, and vice versa.
- A very specific sub-species of the medicine show shill is the toad-eater, a person who would swallow a live toad and be "cured" by the salesman's elixir. Professional toad-eaters would either use sleight-of-hand to hide the toad, train their toads to not excrete poison while in the toad-eater's mouth, or simply bank on the fact that a young, fit, well-fed man will get horrendously ill after eating a toad, but probably won't die. The term "toad-eater" (usually shortened to "toady") is now part of the English general vernacular, meaning someone who will do anything, no matter how disgusting, for their boss.
- David Manning, a film critic for the Ridgefield Press (a weekly Connecticut newspaper established in 1875) who gave good recommendations for Columbia Pictures films A Knight's Tale, Hollow Man, Vertical Limit, The Animal, and The Patriot beginning around July 2000. When Newsweek reporter John Horn tried to track down Manning, he discovered that the paper had never heard of him in reality, Manning had been created by Matthew Cramer of Sony's marketing division, a fact which came out around the same time it was revealed that Sony had employees pose as moviegoers in ads for The Patriot.
- ...And then Sony got taken to court, where they settled for offering $5 refunds to anyone who was unsatisfied with the films Manning "recommended".
- Lee Siegel, a columnist for The New Republic, self-destructed his career in a rather spectacularly brazen display of shilling, wherein he'd blog as himself and then loudly and vituperatively defend his ideas to his many online critics pretending to be an anonymous stranger called "sprezzatura" (a mixture of the Italian words "sprezzo" (despise) and "spazzatura" (trash)). Little, subtle gems like "You couldn't tie Siegel's shoelaces" make it a mystery how the hell he didn't get caught earlier. The most ironic and annoying part of this is that the fallout over this somehow not only failed to prevent Siegel from writing a self-serving book about how the blogosphere sucks and people on the Internet suck and online culture sucks and "blogofascism" ruins everything, it then went on to get mostly favorable reviews from folks in the New York Times and elsewhere. It's like when they let Jayson Blair write a book talking about how much newspapers suck.
- Science fiction writer Kevin J. Anderson does this, and quite publicly. His site, aptly named the "KJA Special Forces", asks members to post blogs, links, discussions, and reviews on online stores such as Amazon in support of both him and his work. Doing so can land you "points", and in exchange for those points you can "earn" prizes and money.
- The director of notoriously bad Limbo of the Lost has been doing this. Then things get kinda confusing.
- Sock Puppet shills are an occasional danger of Amazon (and similar site) reviews. One of the more notorious (mentioned in a David Langford column under the name "Bob Direhack") not only appears to have praised his own books under multiple aliases, but written savage one-star reviews of other fantasy authors, claiming them to not be a patch on J. R. R. Tolkien, Robert Jordan, George R. R. Martin or, er, Bob Direhack. More rarely the reviews would praise an author by claiming they deserved to be in the same exalted company as, yes, Bob Direhack.
- If you are researching a product and Google "[Brand Name] reviews", buyer beware: Investigations have shown that the top sites on search engines are often strategically optimized AstroTurf sites sponsored by the company themselves, or review sites that get kickbacks from the companies by using affiliate links.