Thank you for this, Mike - I'm just now starting to dive into WMT to try and piece this all together...and see some #'s that I can't explain by any rational measure. For example, WMT is telling me that the search term that produced the 5th most impressions is: wastes. And it tells me that the Avg. position for that search term was 5.0.
Now that makes very little sense. There's a page on my site that features an AMA with a waste management professional, which is my best guess as to why my site was deemed relevant...but "wastes" is just WAY to generic a word (and our site nowhere near well-trafficked enough) to bring up our site in an average position of 5.
What can you think of that would explain this??
**similarly, there are plenty of other seemingly way-too-generic-to-be-true queries that WMT is returning abnormally high Avg position numbers for, i.e. photographer picture (4.0), TV editor (11), etc. For every one of these high rankings, I can think of somewhat-related pages on our site that are at least relevant to the query...but nothing that would justify the absurdly high avg. rank that WMT is reporting.
(moreover, on the Top pages tab of WMT, many of my site's pages do not have the little black arrow next to them...so while the waste management professional page is my best guess as to why Google thinks "wastes" is relevant to my site, there's no way of checking this, right? Why do some pages have no black arrows?)