Site owners have been focusing on Google PageRank which should not be the case. You could also use conversion rates and ROI. Google have in fact removed it from the data in the Webmasters’ tool. It’s not as important as it is. They only update Google Ranking a few times a year as indicated in the Google Webmaster Help thread:
“We’ve been telling people for a long time that they shouldn’t focus on Google PageRank so much; many site owners seem to think it’s the most important metric for them to track, which is simply not true. We removed it because we felt it was silly to tell people not to think about it, but then to show them the data, implying that they should look at it. :-)” – Susan Moskwa, Google Employee
All this time site owners and webmasters have been having the wrong notion. They think that the higher the PageRank is the more important your site is. This could stop people from focusing too much on PageRank and more on the relevancy of the content. Though admittedly, we could not change the perception of the people overnight.
There is far more important Key Performance Indicator (KPI) to choose from to say how well your site is performing. Like for example, conversion rate, perhaps you have a huge traffic to your site but are these converted to sales? Or are these Visitors your target market. Site owners and web masters could use Analytics to monitor website performance using different metrics. In fact, it was also stated in Google Webmaster Central FAQ Crawling, Indexing and Ranking as follows:
Q: My site’s PageRank has gone up / gone down / not changed in months!
A: Don’t worry. In fact, don’t bother thinking about it. We only update the PageRank displayed in Google Toolbar a few times a year; this is our respectful hint for you to worry less about PageRank, which is just one of over 200 signals that can affect how your site is crawled, indexed and ranked. PageRank is an easy metric to focus on, but just because it’s easy doesn’t mean it’s useful for you as a site owner. If you’re looking for metrics, we’d encourage you to check out Analytics, think about conversion rates, ROI (return on investment), relevancy, or other metrics that actually correlate to meaningful gains for your website or business.
Which are you going to use as a metric really depends on what is important to your business. In the end you should always measure you’re success in terms of optimizing your site by comparing your website performance vis-à-vis operational performance – end result.