Why it matters to a buyer
A sitemap does not make Google index a page, but it is a direct, reliable way to tell Google a URL exists, which matters most for large sites, new pages with few internal links yet, or content behind a search form a crawler would not otherwise find. For a buyer, a stale or inaccurate sitemap, one still listing pages that were deleted months ago, or one with fabricated last-modified dates, actively works against a site, since Google treats a sitemap's reliability as a signal in itself.
How it is measured or applied
A sitemap should list only canonical, indexable URLs the site actually wants ranked, excluding noindexed, redirected or duplicate pages, and its lastModified dates should reflect genuine content changes rather than being set to the current date on every regeneration to appear fresh. Large sites split their sitemap into multiple files referenced by a sitemap index. It is submitted through Search Console and referenced in robots.txt, and its health is checked in Search Console's sitemaps report, which shows how many submitted URLs were actually discovered and indexed.
Sources
- Build and submit a sitemap, Google Search Central
