How important are key words to increasing adsense earnings?

Keywords are the most important SEO element for every search engine, they are what search strings are matched against. Choosing the right keywords to optimize for is thus the first and most crucial step to a successful adsense earnings.

Good. The first way to improve the ads showing is to improve your ranking in search engines. Keyword research for high ranking words in your industry or field is important. To put it simply: better keywords = more traffic = better ads showing = more YouTube ad money.

You have to find the right and valuable keywords for the site of each page to rank your site with high traffic keywords. Then you have to rank your content with your keywords in the SERP. Just because of more traffic that means more options which can make it possible to earn a valuable amount from Adsense.