High concept

High concept. What a buzz term in the writing industry. & what is it exactly? I've had it explained to me in several different ways. The way that made the most sense to me, well, on a writing loop a gal whose opinion I trust says that explanation isn't accurate. So now, I'm left wondering, what is high concept???

Okay, the explanation given originally was to relate it to something within the media that's well known/of interest, such as a movie, world event, etc. For Jane Millionaire, I've always said my high concept was "Miss Congeniality meets Joe Millionaire". Apparently this is more of a tag line rather than a high concept per the discussion taking place on the writing loop. However, for my story, I think the above fits. Perhaps it's more of a way to set a stage in the person's mind I'm pitching the story to. I mean, for Jane, it's an undercover cop who's a big tomboy who goes undercover on a reality television show to save her sister's butt. Perhaps it could be argued that it's the 'reality show' twist itself that is the 'high concept'.

So, I'm wondering, what does high concept mean to you? What's your definition? Or ideas on this? I'm off to read Diana Peterfruend's explanation at The Knight Agency's blog, as I hear it's an excellent explanation. Very curious as to how others view this term.