[Shog9]

The core of the problem there is that for Gregg, "this site might be helpful" is an understatement; he knows there is a good chance that it will be helpful, that there is direct relevance...

...and then there are the legions of folks who've been posting links to the first Google result with that same text for years. Those are over-selling it: sure, the link might be helpful, buuuut... Probably not. These have been the bane of many a forum, clogging up the first page or so of responses, sometimes discouraging folks with actual knowledge of the topic from even bothering to respond.

There needs to be some way of distinguishing between the two.

[exporectomy]

Maybe we're supposed to consider how many reputation points the person has to judge the likely quality of their link. Those kinds of decisions are already built into StackOverflow with rules on who can write comments/etc. Maybe they just need tweaking so that posting a URL in a comment requires even higher reputation. If you don't have that reputation, you can do the harder work of writing an actual answer that includes the link.