Part of the solution is writing content for which advertisers pay for the key words AND people buy the products that are related to it.
For example, my hubs on business processes get ads for business consulting and office products. Those hubs generate ad income.
My hubs on IEEE standards generate many views because it is hard to get info on those standards without paying the $200-800 for the standards themselves, while you see advertising for books and seminars on those industry standards.
Writing fiction won't result in ads that pay you OR many visits.
Writing generic advice hubs won't turn into ad revenue because bigger sites get more preference in Google search results pages.
Writing overly commercial content will get you down ranked as spam.
So you have to write something that brings readers and has natural tie ins advertisers can sell to them.