bramley - 4:06 am on May 1, 2011 (gmt 0) [edited by: bramley at 4:52 am (utc) on May 1, 2011]
In short, shallowness is the key; per page and per site. With shallowness being the ratio of useful content and sensible layout and navigation versus advertising (position), and content that is repetitive or stuffing (oversight or gaming), or not of real general interest (pages that should be no-indexed to reduce site-wide shallowness).
To put in another way, shallowness is the absence of quality.
oh well, forget it ... whatever ...
[edited by: bramley at 4:52 am (utc) on May 1, 2011]