Just like the deal says - 20% of total purchase cashback if your purchase is less than $1,000 or if it's above that then $200 cashback.
Note this is valid for domestic as well as international which makes it a better deal for me.
Checked out a fare I'd booked a month ago with another provider and I could have saved $200 - uuurrghhh. Anyway, that's no reason not to tell all you about it ;-)
Great deal, with the Webjet $150 Paypal cashback offer brought RT flight to NY to 1040. With this deal, brings it to $908.