With most modern analytics packages the conversion rate can be calculated within the system fairly easily if you’ve set up the appropriate goals and tracking.
Conversions are any event which you consider to be a goal of the website.
For most e-commerce sites, this will be a sale. For other sites the outcome the site needs may be to get the visitors’ email address, for the user to leave a comment, download a file or to click a particular link.
There are two calculations commonly used to calculate the conversion rate. One is to take the total unique visitors over a period and divide by the number of conversions.
The other is to take the conversion amount and divide into the number of visits.
As Google Analytics calculate conversions based on the later process, using visits rather than unique visitors we encourage our clients to do the same.
To be honest it doesn’t matter which calculation you use as long as you are consistent within your on going reporting.
The real purpose of calculating the figure is to have a measurement so we are able to track and record variance in the conversion rate over time.
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