Conversion Ratio
The conversion ratio of your website is the number of sales/emails/goals divided by the number of unique visitors to your website.
If you sold 250 products in a month and had 10,000 visitors that month, your conversion ratio would be 250/10000 * 100 = 2.5%
Think of getting more traffic to your site as one side of the coin and fine tuning your site to produce as many leads/subscriptions or sales as the other.
By analysing the keywords people use to find your site, the landing pages they arrive on and the “call to action” that they are presented with a picture begins to emerge of how useable and sticky your website is.
Creating “conversion paths” through your site or even just making landing pages relevant to the keywords that brought the visitor their in the first place can have a dramatic effect on your conversion ratio.
Small changes can have a big effect, take the example above, by raising that conversion factor by ½ a percent there would be another 50 sales per month, every month and the higher conversion ratio would also benefit all the work done to get more visitors.