Brad,Does Google rate the QS for a keyword by taking into consideration the overall relevance of the other keywords in the campaign? Or is it scored strictly on the relevance of that particular keyword only?

Looking for strategy on content/display network conversion optimization. Even after getting a fair amount of traffic with display, conversion rates are lousy and I find that there is usually no significant ROI. I’m sure there are advertisers that are successful with display, so I’d like to see more information about that topic.