I've used these papers to advertise the lessons described on this site and have made several sales through them. The best results seem to come from Fremantle Herald and Perth Voice (both put out by the same company). Placing classified ads in Post papers also seems to work, though not as well.
The best thing about these publications is that they're very cheap. I can put a four line ad in the Fremantle Herald for fifteen bucks a week. You almost don't notice that. The Post is even cheaper (although it has a smaller circulation).
I haven't yet used the West Australian classifieds. Of course that paper has enormous reach compared to these smaller publications. But are the ads read as widely in comparison? I'm not convinced. I had a friend who took out an ad there once which set her back quite a bit (I think it was a quarter pager). No calls at all.
The sales people highlight the fact that this paper covers the entire state. While that would be a bonus if you had a big business with outlets and offices in many population centres, it wouldn;t be the case if you just had a small, locally oriented business. If you ran such an outfit and advertised in The West most of the people who saw your ad wouldn't end up buying from you even if they wanted too because they'd be too far away! But you're still paying for their views. Ads placed in smaller but much more locally oriented publications will therefore tend to get you much better value for money.
Because local papers are so cheap, you only need the odd sale to make advertising in them worthwhile. Then you can keep tweaking the wording for best results. And I think this is a very important factor. As well as having your ads in the right category, you've really got to have a compelling, short headline that zeros in on your market. Finding just the right one for what you're offering is easier said than done and can take several rewrites.