According to Google AdSense policies, publishers are not allowed to place ads on pages that are under construction, ads on pages that contain excessive advertising, or ads on non-content-based pages. It is also against AdSense policies to place ads on pages that primarily promote the sale of products or services. Therefore, placing a "For Sale" banner on a website with AdSense ads may be considered a violation of AdSense policies.
It is recommended to review the AdSense policies thoroughly and contact AdSense support if you have any doubts about your implementation. Violating AdSense policies can result in the suspension of your AdSense account, so it's important to ensure compliance with their policies.
