Who whoa Whoa!
It doesn’t promote the game. It promotes the other product, whatever it is.
It is not like people who are on Discord see that they can get a skin for a helmet in World of Warcraft and immediately feel an urge to play World of Warcraft.
What does happen is that people who play World of Warcraft see that they can get a skin for a helmet in the game if they sign up for Discord and try out its streaming feature. And for Discord there is a possibility that some WoW players will appreciate Discord and its streaming feature enough that they’ll keep using it.
I mean, understand who makes money off of who in these cross-company promotions.
It’s not Discord who gets money from Blizzard. It’s Blizzard who gets money from Discord.
Blizzard basically approaches Discord and says:
“If we give you exclusive rights to this in-game item, and you give us a pile of cash, then we guarantee a certain amount of WoW players will sign up for your service.”
And then Discord says: “That’s a deal!” because they want more people on their platform, and this is an easy way to get that, and it only costs them a little penny. That’s as good as spending that money on regular advertising.
It’s the same deal Blizzard approached Amazon with. We give you the rights to these TCG items and you give us a pile of cash and we guarantee that a certain amount of WoW players will sign up for your Prime membership.
“Deal!” says Amazon, because they want more people to sign up for Prime.
We - the WoW players - are the commodity that Blizzard are selling. They’re making money off of us by “selling us” to other companies. Twitch, Amazon, Mountain Dew, Trolli, Steelseries, Discord, and so on. They all pay Blizzard money to get…us. And they do get us.
And because Blizzard really wants to make money these days, they are making a lot of these cross-company promotions, because it’s a way for them to earn money.
Edit: And for the record, I would rather that these items were earnable though gameplay in the game, with no external hassle required. Obviously.