Originally Posted by
AA_EXP09
The difference is that the ETA can be obtained for free through the GDS system. Many travel agencies will give one for free, given that you buy a ticket to Australia from them.
This cannot (and I have seen very long queues to clear immigration at SYD...)
And some airlines have given Australian ETAs/evisa for free because they could file them without being charged for them. For example, United used to do the ETAs without charging customers -- at least those in business class on UA flights. AFAIK, there is indeed no such option for the Canadian or US ETA/ESTA/evisa.