Help me understand this a bit -- why would a subreddit buy advertising? Is there a feedback loop or revenue share with mods? Or is this purely a ponzi thing wh

Help me understand this a bit -- why would a subreddit buy advertising? Is there a feedback loop or revenue share with mods? Or is this purely a ponzi thing where you buy bitcoin worth 100 bucks, spend 100 bucks on advertising and end up with the same bitcoin now worth 1000 bucks.