I've ran services with a lot more traffic which didn't make even close to that figure. I would think he makes significantly less than that, but still makes a nice living (on auto pilot).

Doesnt matter if you have a site with more traffic. What matters is the niche/market. You could have a site with a billion visits a day but if its about basket weaving you are going to have a harder time than a site like his with massive exit clicks. The number for ads is if anything, lower than it likely is.

I feel decently confident in my estimate due to my knowledge of the space and my own, current, experience in this space but feel free to retort if you have additional data.

Can you elaborate? What CPM do you think he's getting on these ads?

I'd expect that he doesn't have a particular niche beyond music or music video, and in my experience as you gain more traffic the CPM price that you can command actually goes down and not up.

Facebook only has a CPM of 30 cents to 50 cents.

I would also be interested to hear more.

500k a month in 30m pageviews implies he makes almost $17 per 1000 pageviews. I currently see two ads on his homepage, both large but for the same advertiser (an untargeted credit-card advert). I find it staggering people are selling ad-space at such a price unless it's highly targeted to a specific niche.

Most people do more than 1 pageview-

Also, multiple ads per page = multiple ad impressions.

So while he only has 1m uniques a day, that could be 1.5 visits per user (a unique could covert 10 videos and would only be counted once) so guesstimate 1.5 visits per unique

So now we are at 1.5m impressions a day.

Now, lets count in we assume 3-5 pageviews per visit. So, on the low end thats 4.5m impressions a day.

He has multiple ad units, you counted two. So now we are at 9m impressions per day / 270m per month

Makes things much more sane. Also, I went on the low end of numbers. Its more likely he does well over those numbers.

Kudos to him if he does. Shame we won't know for sure :) I would say it's <= 50k/month with that kind of site/traffic/ranking, but maybe you have more insight. The conversion will be horrible so his ad provider(s) will drop price over time.