Essentially, that's correct. I think that in the United States it's valid for two years. In Australia, it's valid for one year.
We think that a longer period of time that corresponds with where we want to go and where we have been going on the temporary resident visa side—by issuing multiple-entry visas for a maximum validity of 10 years if the passport allows it—only makes sense in terms of client service and being facilitated for travel to Canada for legitimate travellers. A multiple-entry or long-term duration eTA makes sense to us, but it of course can be withdrawn if adverse information comes to light during that period.