Google AdWords used to be the internet standard for advertising. Hiring a firm to optimize your website so you would rank closer to, if not at, number 1 in search results. Adding in AdWords gave you an additional edge.
However, Facebook has been upping the ante with their advertising campaigns. Creating very desirable features for businesses to use in order to get their business in front of people.
Each of the sites change their algorithms frequently. Google shifts their requirements to rank high and Facebook changes what shows first in their users’ News Feeds.