austtr - 3:30 am on May 27, 2010 (gmt 0)
Relevance is such a wide open term. It means different things to different people... and algos.
The human mind probably thinks it's relevant for that Toronto hotel site to link with Toronto apartments, Totonto car hire, Toronto tours, Toronto flights, Toronto cruises etc... because we understand they are all part of a broader "travel and tourism" marketplace and may add something to your viewers experience.
But there isn't any relevance associated with Toronto Funeral Homes, Toronto auto parts, Toronto body shops, Toronto lingerie shops etc. Why would the word "Toronto" get you any brownie points for links that obviously add nothing to the viewer experience? Ditto for those Paris hotel sites... Paris is not relevant to Toronto even if both sites are about hotels.
It would be a pretty poor state of affairs if the algo can't make those sorts of distinctions and I'm going with the arguments that says they can.
One other aspect of linking that does not get a lot of air-play in here is having lots of links vs having fewer links.
For years I have followed the mantra of "quality is best" and have collected a sold base of relevant, on-topic links with a good proportion having decent PR. My links total in the hundreds. The sites that put me in the shade have thousands of links, mostly PR0, many off-topic and with very heavy cross-linking between sister sites.
That is not a "woe is me" whinge, but rather the sort of thing that makes me think link quantity, irrespective of "relevance", plays a much bigger part in the very competitive niches than we openly acknowledge in here.
I'm not convinced that Google is as good as it thinks it is in determining link relevance, or quality, and when it has to rank two similar sites, the one with the most links seems to have a head start on the higher ranking.