Google.com vs Google.ca vs Google.co.uk (etc) all rank their results differently. The intention is to return more locally-relevant content.What factors, other than the ones below, are used to determine local relevancy?I already know the TLD (.com, .ca, etc) and likely the server IP address is used but there has to be more as this would not explain some search results I noticed this week. Particularly, I see a US-based site ranking #3 for some keywords on Google.com, ranking #5 on Google.ca and not ranking within the first pages on Google.co.uk. On Google.com it outranks a Australian site which outranks it on Google.ca. The site itself is relevant for all English-speaking locations and it being outranked by sites from different regions on different Google TLDs (but not ones from the same region as the TLD).
What Ranking Factors Are Used For International Search?
seo;top level domains;ranking;international
Google: Working with multi-regional websitesGoogle generally uses the following  elements to determine the geotargeting  of a website (or a part of a website):Use of a ccTLD is generally a strong signal for users since it  explicitly specifies a single country  in an unmistakable way.orWebmaster Tools' manual geotargeting for gTLDs (this can be on a domain,  subdomain or subdirectory level); more  information on this can be found in  our blog post and in the Help Center.  With region tags from geotargeting  being shown in search results, this  method is also very clear to users.  Please keep in mind that it generally  does not make sense to set a  geographic target if the same pages on  your site target more than a single  country (say, all German-speaking  countries)  just write in that  language and do not use the  geotargeting setting (more on writing  in other languages will follow soon!).Server location (through the IP address of the server) is frequently  near your users. However, some  websites use distributed content  delivery networks (CDNs) or are hosted  in a country with better webserver  infrastructure, so we try not to rely  on the server location alone.Other signals can give us hints. This could be from local addresses &  phone numbers on the pages, use of  local language and currency, links  from other local sites, and/or the use  of Google's Local Business Center  (where available).Note that we do not use locational  meta tags (like geo.position or  distribution) or HTML attributes for  geotargeting. While these may be  useful in other regards, we've found  that they are generally not reliable  enough to use for geotargeting.Other then giving more weight to local web pages the ranking factors are the same. It is important to note that being in a specific country doesn't mean you'm automatically rank well or better then non-country specific web pages. Quality of content still is the most important factor.