Factories are twice as efficient. "You're going places."
Own 5 factories
Factories are twice as efficient. "Cheaper, healthier workforce."
Own 25 factories
Factories are twice as efficient. "Slackers will be terminated."
Own 50 factories
Factories are twice as efficient. "Gives your cookies a healthy glow."
Own 100 factories
Factories are twice as efficient. "A major part of cookie recombobulation."
Own 150 factories
Factories are twice as efficient. "A patented process increasing cookie yield two-fold for the same amount of ingredients. Don't ask how, don't take pictures, and be sure to wear your protective suit."
Own 200 factories
Factories are twice as efficient. "Semi-synthetic organisms don't slack off, don't unionize, and have 20% shorter lunch breaks, making them ideal labor fodder."
Own 250 factories
Factories are twice as efficient. "Why didn't we think of this earlier?"
Own 300 factories
Factories are twice as efficient. "You figured you might get better productivity if you actually told your workers to learn how to work the machines. Sometimes, it's the little things..."
Brownie point system
Own 350 factories
Factories are twice as efficient. "Oh, these are lovely! You can now reward your factory employees for good behavior, such as working overtime or snitching on coworkers. 58 brownie points gets you a little picture of a brownie, and 178 of those pictures gets you an actual brownie piece for you to do with as you please! Infantilizing? Maybe. Oodles of fun? You betcha!"
Own 400 factories
Factories are twice as efficient. "If you're bad at something, always do it for free."
Own 450 factories
Factories are twice as efficient. "Through careful social engineering you've convinced your workers that "union" is a slur that only the most vile and repugnant filth among us would ever dare utter! Sometimes progress isn't in the big machines, it's in the little lies!"
The infinity engine
Own 500 factories
Factories are twice as efficient. "In this house, I guess we don't care much for the laws of thermodynamics."
15 factories and 1 grandma owned
Grandmas are twice as efficient. Factories gain +1% CpS per 3 grandmas. "A nice worker to manufacture more cookies."
15 Factories, 15 Antimatter condensers and "Synergies Vol. I" purchased
Factories gain +5% CpS per antimatter condenser. Antimatter condensers gain +0.1% CpS per factory. "Your machines won't even be sure if they're on or off!"
75 Factories, 75 Time machines and "Synergies Vol. II" purchased
Factories gain +5% CpS per time machine. Time machines gain +0.1% CpS per factory. "Introduce more quickitude in your system for increased speedation of fastness."
75 Banks, 75 Factories and "Synergies Vol. II" purchased
Factories gain +5% CpS per bank. Banks gain +0.1% CpS per factory. "Fake bills so real, they're almost worth the ink they're printed with."
75 Factories, 75 Shipments and "Synergies Vol. II" purchased
Factories gain +5% CpS per shipment. Shipments gain +0.1% CpS per factory. "Where carpentry, blind luck, and asbestos insulation unite to produce the most dazzling spaceships on the planet."
Random fortune from news ticker
Factories are 7% more efficient and 7% cheaper. "True worth is not in what you find, but in what you make."
In Cookie Clicker Classic
Two images from the Classic version, left: icon shown in the store, right: appearance in the middle field
The Factory is the third-cheapest item you can purchase. It will give you 20 cookies every 5 seconds. It costs 500 cookies to start and will increase by 10% each consecutive purchase.
Purchasing your first Factory increases Grandma output by +1 Cookie per 5 seconds. It will also cause some grandmas to wear blue work suits and yellow hard hats.
Factories will be the first buildings to have their dungeons.
Factories are the first building to reach 1,000,000,000,000,000 (1 quadrillion) at 200 buildings purchased or less.
When you have 50 Factories on the beta (v.1.037 beta), you unlock Dungeons.
In Cookie Clicker Classic, the mines were unlocked after the factories, but in cookie clicker update 1.0 this was changed the other way around.
The achievement "The incredible machine" likely refers to the series with the same name, "The Incredible Machine".
The achievement "Rise of the machines" is a reference to movie Terminator 3: Rise of the machines.
The achievement "Break the mold" is a reference to the song "All Star" by Smash Mouth
The flavour text "If you're bad at something, always do it for free" likely references the DC character The Joker saying "If you're good at something, never do it for free".