The ETA is a tool that will make things easier, especially in terms of security. We expect that visitors will be screened somewhat more rigorously at ports of entry than they are today, given that they will have undergone risk assessments before leaving, while on the plane and upon arriving in Canada.
This process, or tool, enables us to address abroad half the risk travellers may pose before they leave for Canada, while still overseas. Because people in possession of an ETA who travel to Canada relatively often will have undergone a risk assessment and have provided data, we can respond more efficiently once those people are in Canada.