I'm curious: how does Reddit profits from anything?

It seems to me the only revenue they seem to have is ads?? But I use it on the web and never seen ads (except for actual posts that are ads, but those usually get quickly downvoted and I don't even see most of them)... I think people who use Apollo or other apps also like to use Reddit on those because, among other things (like nicer UI) they do not show ads (and probably don't make any money either). Hence, it seems to me, perhaps naively, Reddit is giving us stuff literally for free.. they can't even monetise user data like Facebook, as most of us are anonymous users...

So, would be really interesting to understand how they're making money, which could help understand their motivations here.