Over the past 15 years I've been running forums, Adsense beats them all for plain banner advertising. There are some companies in the UK who are nearly competitive for me for over 2.5 million impressions per month across all my sites, but Adsense is still the boss!
IP.Content is a massive uphill learning curve. I've been there, and struggled up the hill. Luckily at the time I had plenty of time to learn. Now that I know what it can do, it is bloody powerful.
It runs my homepage: http://www.talkford.com/page/index.html
It runs my car reviews: http://www.talkford.com/page/ford_reviews/_/ford-mondeo-reviews/mondeo-mk3/
It runs my wiki (still being built - but a wiki CAN be done via IP.Content quite easily): http://www.talkford.com/page/fordwiki/fordwiki.html
It runs my dealership reviews: http://www.talkford.com/page/Dealership%20Reviews/_/east-anglia-ford-dealerships/roy-chapman-limited-berkhamsted-r339
The biggest problem you'll find, if you're a non-coder like me (i'm a bodger and tinkerer) is actually finding people who are competent enough to create what you want. They are very far and few between, either too busy or too unreliable. A basic database is easy to setup and run, but if you want it customising to make something like my car reviews, that's where it gets a little bit more challenging. Although saying that, after much practise and bodging, it does become quite easy, as the templates are just a mix of HTML and some IPB stuff. The problem being if you're new, is knowing what the IPB stuff is! I've been playing with it for about 3 years now, and I'm still learning stuff every week with it.