How do content freshness & relevance impact SEO performance, & how frequently should content be updated or refreshed?

Content freshness and relevance are extremely important factors that can significantly impact a website's search visibility and rankings. Search engines want to surface the most timely and authoritative results for any given query.

For topics and keywords that are particularly time-sensitive or where information goes outdated quickly, having fresh, up-to-date content is essential for SEO. Things like news, current events, product details, regulations/laws, data/statistics and rapidly evolving industries are examples where outdated info gets pushed down.

Google has stated they use "query deserved freshness" signals to determine when fresh content should be prioritized based on the nature of the query. Searches including words like "recent", "latest", "new" etc. trigger higher freshness prioritization.

However, even for broad informational topics without obvious freshness needs, frequently updating content with new insights and multimedia keeps it feeling authoritative and useful.

As for optimal content update frequency, there's no one-size-fits-all. It depends on the content type and the topic's freshness demands. But in general:

• Time-sensitive topics: Update at least monthly, if not more frequently

• Regularly changing topics: Quarterly updates at a minimum

• Evergreen informational content: Update comprehensively 1-2 times per year

The key is monitoring changes in your industry, search demand trends, analytics to identify outdated pages, and continuously expanding scope with new angles.

Combining a strategic content refreshing plan with technical optimization for freshness signals like frequently updated sitemaps can provide a significant SEO edge over out-of-date competitor content.