incrediBILL - 4:29 pm on May 4, 2013 (gmt 0)
It is my opinion that penguin is keyword specific, not so much a "domain" penalty in traditional thinking. We still rank very well for many keywords.
I doubt it's keyword specific but may have targeted specific keywords on your site.
Remember, this is stuff from the anti-spam team so if one of your keywords looked spammy within the definition of their algo then POOF! you lost a keyword.
Why you probably still rank for others is perhaps you didn't try as hard for those keywords and they looked less spammy to the algo.
What's probably more amusing is people not knowing Panda/Penguin weren't updating daily probably fixed their site, broke it, fixed it, never saw changes because they didn't understand it only ran now and then, and have no clue because obviously nothing ever changed because nothing was changing.
I'll be a lot of clients have spent a lot of money on a lot of consultants tilting at this windmill and, depending on what they did, got no measurable results if the site was primarily kept in the status quo. Maybe I'm wrong, but that's what tends to happen when people start thrashing without all the facts.