I'm probably way behind the times in seeing this (or perhaps we do well enough on our search terms for our sites that I've never noticed ;)); but thought I'd mention it.
Before I get to the detail; I have seen similar things to the detail below, but not quite the same thing; such as 'did you mean', 'would you rather search for xxxx instead' etc. (intrigued yet?) OK, onwards and, well hopefully, upwards.
Last Friday I was just doing some rank tracking for some fairly random terms (well, it was late on Friday, what else do you do?) and eventually realised that Google had decided to take the search term I was looking at and had ADDED the results from a 2nd search term (very similar, so sort of see why) to its SERPs for my search term without any mention of it (in the first instance). So, if you had been optimising for the one search term, and you were looking to see where you result ranked, then it may well have been that you came away thinking:
Poot!
Here's an example:
(nb. all searches were in UK on google.co.uk)
I did a search for 'reclaim care home fees solicitors'
Clicked through to page 3 and I saw the following:
"
Including results for claim care home fees solicitors
Search only for reclaim care home fees solicitors
"
So, I wondered, when was Google adding a 2nd search terms' results to the mix?
Now, I thought it could be that Google only added the results at page 3 or greater (a bit like the options I've seen before, but automated); so:
I Noted the number of results returned: 1,600,000
I then redid the search and looked at page 1:
Noted the number of results returned: 1,600,000
The same - so it looks like, for the search term I was looking at, Google have 'added in' results for a different (though closely related) search term STRAIGHT AWAY BUT with no mention of this fact on page 1; and in fact it was only at page 3 did Google think, hmmm maybe I shouldn't have added those extra results and let you do a search without them.
To check I then re-did the search term with the 2nd term excluded and, low and behold, vaslty fewer results returned. SO, yup, looks like I was right.
Now I've only seen this once (or at least noticed it once), on this occasion, but it makes me wonder how often it is happening and I haven't noticed. I appreciate Google has had similar options for adding other results to those originally returned for my search query, or switching to a new search term, but this was the first time I have noticed the results being added WITHOUT any interaction from myself and without letting me know (until page 3).
The impact for me is self evident, when we do our keyword research and do our on-page optimisation, how often are we missing the fact that Google will be adding in results from a 'different search term' that we haven't optimised for and which could push our result much lower?
To take a quick look, I took the instance above and picked a site from about page 8 that seemed to be optimised purely for my original search term and re-did the search with the 2nd result set removed and surprise-surprise, the site I had picked jumped to page 3. A big jump.
So perhaps some of those search terms we just can't seem to get ranking as we would expect, when we compare our sites to those above us, particularly on page 1, aren't where they are because the other sites are 'better optimised' than ours for our search term, but because they are optimised for a completely different search term that we haven't optimised for at all!
Am I behind the times with this? Anyone else seen this? Just wondering.