Content is king only if you have exact and highly specific keywords placed in correct locations. Unfortunately, the hard part is determining what keywords to use. A keyword can be a single word or a phrase. It is the term that internet surfers use to search for information. Place yourself in their shoes and try to discover what search terms they use. You must then evaluate the search term.
How many people search using that term? How many sites already deliver information on that search term?
Simple demand and supply rules. The more demand with the less supply equals more profitability.