Google's John Mueller was asked about when it makes sense to host images or other content on separate subdomains or domains. John said it makes sense if Google is having trouble crawling as much as it wants to crawl.
John wrote on LinkedIn, "If Google has trouble crawling as much as it wants to crawl due to technical reasons, then splitting the load across subdomains or domains makes sense."
It doesn't just have to be for images, he said "sometimes this makes sense for any kind of static content regardless of Google's crawling (many sites have static content CDNs)."
But it doesn't matter for most sites, he said, "For most sites, this isn't needed." Plus he said "it won't push Google to crawl more, and more crawling doesn't mean better ranking."
Yea, crawling more does not mean better rankings.
And a follow up question was on a "prioritization queue," in which John replied, "I'm not sure what you mean with "prioritization queue", this is really more of a technical measure. (look up "cookieless subdomains for static content" for example)."
Here is that post:
Forum discussion at LinkedIn.
