keywords with a bounce rate of 90% and up are candidates for removal.

What would be the point of measuring ROI and conversion rate when a bounce rate of 90-100% tells you the visitor is not interested?

Bounce rates of 50-60% are not that bad.

Likewise, I think ROI is the most important, then conversion, then bounce rate.

The bounce rate can be a bit deceptive. Most of my sites get serious traffic from design galleries ( such as CSS Remix ) and this traffic pushes the bounce rate up by up to 50% - 60% because most of the hits only stay on your page for a few seconds. The CSS galleries are my favourite quick fix for quality links. About a week ago, I was on the homepage of a PR9 gallery :). If you redesign your site often you can really juice them. Even just a handful of gallery links will give you a PR4 and really successful designs can get a few hundred links (including second-hand links). Keeping on the bounce rate topic, the purpose of my homepage is for people to only be there for about 30 seconds and I don’t care if they go straight back to the SERPS so long as I get a quote request.

One thing a lot of sites don’t do is to actually track the source of orders and enquiries. Currently I am working on a search engine related arm of a PHP framework. In this I have an object I create that contains all the information about your visitor - source, keyword searched for, browser etc. I just create a new session with this object if one doesn’t exist and regurgitate it into a database when they order/enquire. This is my favourite performance metric. Its also useful for finding out if your competitors are sending you fake enquiries if you know their IP or they have their own hostname. Unfortunately you can’t see their face when you return their enquiry to them