Why are users worth money if they're barely being monetized? Considering how big (and old) reddit already is, they should already be profitable, and hence shouldn't need to raise money - unless they're planning something radical and expensive. Reddit is a cool site and wildly popular, but that doesn't mean it's going to make billions of dollars.

Also I suspect the site is increasingly populated with bots, not real users. I'd actually imagine the site is less popular this year in terms of real users than it was a year ago, although I have no way to know that and could be wrong. I'd need to see hard evidence to believe it hasn't had a rapidly growing bot population though.