I spotted this for the first time last night:
I had actually read the post in the Google Reader context (so Google knew that), but I wonder: if I hadn’t read the post, would it still have shown up like that?
As far as personalised ranking signals go:
– does the fact that I subscribe to the feed in Google Reader affect the rank of items from that feed in my personalised search results?
– if I have read the post in Google reader, does that also affect the rank of that specific post in my personalised search results?
If I have shared a link – through Google+, or Twitter, for example – are the ranking of those links positively affected in my personalised search results. That is, might social search actually be most useful when the Goog picks up on things I have shared myself, and then “reminds” me of them via a ranking boost in my personalised search results when I’m searching on a related topic?
Maybe tweeting and sharing into the void is actually yet another way of invisibly building search refinements into your personalised search context?