I used to read the Toronto Star online several times a day. The trivia night I go to most Wednesdays used it as the source for questions for the first round every week. Then The Star introduced a paywall. I stopped reading it. The person who runs trivia night stopped using it and switched to the National Post.
It's incredibly hard to monetize casual internet content (e.g. news, blogs, etc.). Charging for access causes a huge drop in readership (depending on the form of paywall: 60%-90% for the Times UK, 40% for the Globe, etc.) and isn't an approach most small websites can take because their brand has no value (yet).
Google AdSense used to offer decent payouts but rates seem to have dropped in the last few years. A series of websites that I run for a client made about $400 from many tens of thousands of views in two years of AdSense. Most of that money was made in the first few months of running the ads (before the $/click went down). Not a great living.
A recent article posted to HackerNews (discussion) gives the author's revenue breakdown by type. Amazon affiliate links were their largest moneymaker by far. This prompted me to finally sign up for an Amazon Affiliates account to try it out for myself.
I think the best way for most people to monetize content is to drive customers to their business (hire me!). One way to do this is to have social media accounts that automatically update as things happen with your website. For example, I have a government monitoring business that automatically posts to Twitter (@OntarioMonitor) using hashtags that my target customers watch (#onpoli).
Obviously the form of monetization will depend on what business someone is in (e.g. a journalist drives leads to their technical writing business). What is clear is that you're not likely to get rich off of passive advertising networks like Google AdSense.
If you want to know more about writing Twitter bots to supplement your social media presence feel free to send me an email at cameronhuff.com.