It is often surprising how many companies have statistics that they simply do not ever analysis or use. Data can be vital to helping with improvements and to find out if there are any issues with your website or web marketing.
One of the popular statistics packages is Google analytics. This program will allow you to see a wealth of information about your visitors such as which pages they visited, how long they spent on a page, if they submitted you and enquiry or completed a purchase. It can even tell you what device they used to view your site.
With this data you can then start to drill down to see which pages are working as well or better than you expected and which are not performing. It may be that by analysing this data you can actually find pages with broken links on or ones that are not displaying correctly, allow you to fix them.
Whenever you do any marketing campaign you need to be able to track if it was successful and often website stats will help you to discover this. You can see if your visits increase, the number of sales you made or the number of enquiries you received went up.