Getting content right is the first step to getting AdSense to benefit you and your site. If your content is without relevant keywords, Google bots will keep ignoring you, which causes Google to link irrelevant ads to your pages. Try to use as many industry related keywords as you can, but ensure that you do not start keyword stuffing in the name of rich content, as it can put a drag on your whole effort.
Google bots are not human and can’t asses the website relevancy by manually reading the content. In order to guard against such errors, Google has devised a way to target certain areas of your page content where you want the ads to appear. In the section targeting, you are allowed to put a certain code around the parts or bits of your content. This helps bots assess the relevancy, giving you the ads you want, consequently helping you improve CTR (click through rate).
Focus on on-page SEO factors
On-page SEO (Search Engine Optimization) factors such as metatags are an effective tool to get the most relevant ads. Right metatags walk Google bots through your site content and help them find the right ads for each page. You should write title of each page according to your industry’s most relevant keywords. Meta keywords and meta description should be produced.