AdWordAccelerator is not just a piece of software but a system that needs to be maintained and updated frequently in order to deliver the most relevant and up-to-date AdWords keyword research to you. This research includes data from various online systems like Google, other top search engines, many top ranked websites, and domain registration servers. Therefore, a monthly fee is charged in order to cover the costs associated with the ongoing updates and improvements that you will continue to automatically receive each time you restart AdWordAccelerator.