I don't really know what you are trying to ask. Can you be more specific so that people will be able to help you.
Is there any way to increase the relevance of your google ads other than SEO techniques...I know the answer is almost assuredly "no"...
The best way is to put an appropriate amount of relevant content on your page. It's something you should be doing in the first place so this really shouldn't be an issue.
No keyword density means no relevant ads -- And no relevant ads mean no smart income... SEO is important only in view to optimize your content with smart keyword density and with such keywords that are high paying... Hope this helps! Good luck,