The goal and meaning of test automation

Many testers know the test automation tools, such as Selenium. Many of them can effectively implement test automation scripts using these tools. But, testing process consists not only of test implementation and execution. If organizations want to maximize benefits from test automation, they should put it in proper step of testing process and proper place within themselves.
In my presentation, I want to talk about the goals of test automation, its meaning, potential benefits and risks. I would also like to show basic principles of well implemented test automation.
I will focus on the following topics:
* why automate?
* what to automate?
* problems of test automation
* basic automation techniques
* when automate?
* maintenance of test automata
The presentation is not bound to Selenium or any other particular test tool.