Wilburforce - 12:33 pm on Aug 20, 2013 (gmt 0)
does it really improve sites?
Joseph Heller is reported to have said: 'When I read something saying I've not done anything as good as Catch-22 I'm tempted to reply, "Who has?"'
Some sites/pages - like correctly coded definitive texts on specific subjects - really can't be significantly improved.
In any event, I get the impression that the most common manual penalty is for unnatural links (i.e. for external rather than on-site content). Penguin extends this to algorithm-based penalties invoked without notice or any auditable offence or solution. We're not being asked to improve our sites, we're being asked to clean up internet spam for Google.