My largest website averaged 500k + views a month with, at the time 30k members. I was only getting around $100 a month from ad revenue. The thing I found got me the most revenue was from paid memberships, and marketplace sales. Hints why there's no adsense on here and only a marketplace and premium membership

The pricing was the same as here, and I had around 50 people with the yearly membership, and about 25 with the monthly membership.
This image also shows how valuable a marketplace can be. This site was and still technically is my largest website ever with just under 40k members. This resource has been purchased 173 times at $99. I take 20% of all sales through the website. That's $3,425.4 for just that one addon itself.
Ads are a great way for that tiny extra bit of income, but if you really want to make profits then I'd suggest going with VIP groups, promoting them and giving them some really good benefits, finding other ways such as a marketplace, paid promotion, etc.