Steam does not sell steam keys to retailers

This

How do retailers run out of keys then? How does Valve make money off Steamworks games outsides of their store? Why would steam generate these codes to give out to retailers if it costs them money maintaining servers? Why don't retailers undercut Valve 100% of the time?
I think it's logical to conclude that Steam does charge retailers for keys.

This however is about developers being granted unlimited free keys to their product when it goes on Steam. There is likely a legal agreement that forbids the resale of these keys outside of the Steamstore either completely or without Steam taking a cut.
Giving Steam keys to people who have already bought the game on another service is essential to get people to vote for the game but benefits Valve as it gets more people using the Steam client and therefore likely using the Steam store.

That's because it's run through Greenlight. That's a benefit for the developers to join Greenlight. If it's not on Greenlight, they have to buy keys.

Not really sure how greenlit games are similar to shops like gamergate obtaining steam keys

Ok, so because Greenlight is working like this, you deduce that the whole steam market for retail is working the same. Nice deduction dude. Hope you're not in the police or a scientist.

i think that is only for green light dude

Hilarious.

Nice, so if I buy from other sites steam gets no money.

"With no licensing fees and no charge for bandwidth, keep your customers up-to-date and together with a unified system. There is no requirement that you sell your game on the Steam digital store."
I still fail to see where it says that Valve doesn't take a cut from steam key generations. One can not charge for licenses or bandwidth yet still charge for keys. Maybe try "There is no per-copy activation charge..."

Also, how exactly is this even important to that discussion? So what if other stores get their keys for/from Steam?

Btw, if you're looking for indirect evidence that keys from elsewhere don't end up in Valve's pocket, look up Borderlands 2 on GMG. It's been effectively 20-30% off since launch. I have no idea how they could maintain that kind of business practise when divvying up the profit between themselves, the publishers, and Valve.

It's surprising, but true. That's one of the things that makes Steam so appealing to developers and publishers. They're a loss-leader, charging nothing for most of the service that they give to sellers. Mainly, Valve takes commission only from the customers they bring in themselves through the Steam Store, and they'll still cover the distribution expenses of sales that you make without their help. On the flipside, this gets more and more people on Steam constantly, which keeps throwing 75% Steam Store specials in their faces - and it's commission on those that keeps Steam profitable. It's a big gambit that turned out to work very well for Valve.

You still have to distribute those keys to other retailers somehow and same goes for first party (the publisher/dev) services. That is the reason why they can run out of keys. You generaly just don't go out giving your master key gen out...

Read these two articles. It seems like they do in fact host games on Steam for free, only making money when the game is sold through Steam.