From my limited knowledge, a google penalty affects your rankings. Let say you rank at position 7 in Google and get hit by a -30 google penalty, then your website will always rank 30 sport below the real position, so in that case in rank 37 A google penalty can be issued on your domain/url because of bad content. Let says you overemphsie on bold text, so it doesnt look natural anymore, or you have way too much links on your page, the google algorithm may make your ranking different then waht it could be with proper on page optimisation.É Google as some suggestion for webmaster and they define what they think is a quality page: See here: http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=35769 Hope my answer helps a bit.