This week and next are what is called in TV a non-survey ratings period. It's when the networks supposedly shut up shop because of Easter, the school holidays, and (sometimes) Anzac Day. In the annual ratings battle, this period of time usually doesn't matter and networks normally "rest" their key programs.
The pre-streaming video thinking behind this is that audience levels will be lower because of the break and holidays and ad rates will be lower -- but costs will remain the same. As a result, the commercial free-to-air TV networks don’t screen their best content and instead hold on to them until official ratings resume. The ABC and SBS compete, arguably unfairly, with the commercial networks by screening interesting programs -- one such example is the ABC screening an episode of British drama series Vera last night, pulling in more than 1 million viewers.