It is recommended that you check your website’s traffic analytics at least once a month, but there are times when it would be prudent to check more frequently. Monitoring your analytics will help you to determine if you are winning the battle for high-quality traffic or if you are still losing out.
Since you will be monitoring your analytics on a regular basis, you will be able to take steps to optimize your website so that you continue to increase the amount of traffic. Another reason to monitor your analytics is so that you can see if there are any major trends in your traffic.
If you notice that your traffic from a particular source is decreasing at an unusual rate, it might be a good idea to do some investigative work into the source to see if there is something out of the ordinary happening.