I would like to know if it's really necessary for every single web page of a website to be seo optimized? I mean do many seo optimized pages boost my ranking in general? Or can I concentrate on the most relevant pages for google search and forget about pages like impressum or product overviews. Because I don't believe my customers would want to get a product overview in google search as a result instead of the product page itself. But maybe google and bing think otherwise.
I appreciate every help, especially with a reference source.