According to https://www.reddit.com/r/modnews/comments/6pxyvy/traffic_pag..., about half of your users are mobile users of the official app, which does not support ad blocking, so at least half of your entire userbase either pays for gold, or has ads. Official statistics you’ve published put reddit at a reach of 6% of US internet users, which would be over 234 million users.
This would mean 117 million monthly users at 4 USD pre-tax each, which would be a monthly revenue that’d rival Google or Facebook. And this is completely ignoring any and all desktop users. So either your user statistics are wrong, or you don’t even get close to the 4 USD revenue per user in ads.
Based on the fact that Reddit officially isn’t profitable, and has 230 employees paid at Silicon Valley wages, and assuming reddit has a factor of 10 less users (so ~11 million mobile users per month, which would assume half of the subscribers to AskReddit would be active mobile users), the actual money you’d get per mobile user per month via ads (again, assuming all desktop users use adblock), would be around $0.21. This also matches much more closely the usual per-user ad revenue statistics.
And $0.21 per month is a price that also is a lot more affordable for people outside of silicon valley. Even a buck a month is still within of affordable range, although less so if you use many different sites. If you visit hundreds of pages per month, paying $4 each would bankrupt people. And no, you don’t get the same revenue via ads either (as explained above, or can be determined via the simple equation that the entire revenue sites you’re visiting make from ads has to be less than the disposable income you spend on products per month).
The population of the U.S. is about 320 million, including children and non internet users, so how can 6% of US internet users equate to over 234 million users?
Reddit operates in many countries, but the data Reddit published on their blog a few months ago named both of these numbers. Which is... interesting.