Tedster, I'm thinking about focus. I have, as I've said, three sections of my site: the retail store advertising, the widget information, and the small ecommerce store. I think the ecommerce store may be confusing Google as to the focus of the site. I've thought this for a long time (last year).
That's the one that I would think would be best to spin off. There's nothing wrong with it. It's been very good for me, and it ranked very well on Google, and still does on the other SE's. It was one of the hardest hit by Panda, though, and it not fitting with the focus of the site is the only reason I can fathom for the type of punishment it got.
Perhaps with that moved to another site, Google would see the relationship between the information about widgets and the ads for stores that sell the widgets (and mention the widgets in their ads).
I don't know if it's too soon to make a radical change like that or not. I'd have to do everything possible to retain the backlinks I've gotten for the ecommerce section. One thing I don't know is if moving that section to a new domain would remove the seniority ranking benefit that established sites have had in the past.