Disclaimer 1: I am currently assisting in the campaign for the Australian Democrats (of which I am a member) in Western Australia. I also used to be a member of the Australian Labor Party, and served as a scrutineer for them.
Disclaimer 2: I banged this out pretty quickly, and I intend to go back and make corrections, add references, etc. later on. You know, when I don’t hate democracy for stealing all my time.
This is known as an informal vote. There’s nothing illegal about it, and many people do it to protest compulsory voting (attendance) in general, or to protest the specific candidates or government of the time. See, while it’s necessary for enrolled voters to attend the polling place and have their name checked off, they’re completely free to do whatever they want with the ballot paper after that. While most of us are putting numbers in boxes — and while I’m trying to figure out how I numbered 55 boxes with 57 numbers — some people write messages in large letters, draw pictures, leave teeth marks… that is, generally render their vote uncountable in some way.
But there are good reasons not to do this, and it basically comes down to this: your vote does more than elect the government.
The party to which you give a  gets paid for it
This is possibly the best kept secret of the Australian electoral process. Your vote is not just thrown in one of two piles and then discarded the minute we know who gets to sit in the comfy seats for the next three years. If a candidate or party gets more than 4% of the primary vote — that is, if they get that many #1’s next to their name — they get $2.30 per vote to spend on campaigning at the next election. So even if your favourite minor party has no hope of getting a representative in, by giving them a primary vote you might well be giving them access to enough money to change the game next election.
There are two houses of parliament, and their votes are counted completely differently
The Australian Parliament actually comprises two houses. There is the House of Representatives (the “lower house”), which is populated like so: The country is divided up into 150 electorates, containing approximately equal numbers of people (for any given state). A party can stand one candidate per electorate, or an individual can stand independently. The entire electorate then gets to vote on who represents them.
The members of the lower house are the ones you generally see on billboards and in newspaper ads, with captions like “local action!”, “representing YOU!” or “I shop where you shop!” (They do, but wearing a mask.)
Whichever party has a majority in the House of Representatives gets to form the government. Yay! But the problem with this system is that you end up with “safe seats” — electorates that have member after member from the same party, such as Curtin, which has elected a Liberal Party member every election for the last fifteen centuries. It can lead to complacency and entire sections of the population being ignored when they’re distributed amongst several different safely held electorates.
And then… Then there’s the Senate. I would hazard that the most obnoxious politicians in Australian history have mostly been senators, and yet it remains a bit of a mystery to many Australians. I don’t know the numbers, but I’m willing to bet that when most Aussies are in the polling booth, they just put a  on both pieces of paper without really knowing the difference. (Maybe I’m being cynical, numbers would be welcome.)
The Senate is meant to act as a moderator for the Parliament — each state gets 12 senators (2 for territories). Legislation has to pass through both the lower and upper houses to become law. This was basically designed to stop, say, New South Wales and Victoria ganging up in the lower house and deciding to paint Queensland yellow for the hell of it.
Currently there are 55 senate candidates in Western Australia competing for these 12 spots.
Unlike the House of Representatives, though, the Senate votes are counted across the entire state. This means that the Senate population can turn out very differently than that for the House of Representatives. Instead of a single electorate voting for one representative, you have a whole state voting for twelve senators. And although this might seem like it evens out, it often turns out that the party with the majority in the lower house — the government — does not always get a majority in the Senate.
If only a few percent of people in some state vote for a minor candidate, they still have a decent change of getting a seat in the Senate. It doesn’t matter if those few people are spread out across the state, or if some of them live in “safe seats” (electorates not likely to change party hands). It is a completely independent counting process. The electorates do not matter. The lower house candidates do not matter.
This is such an important point, and so few people get it: There are NO safe seats in the Senate.
And if you feel that 55 candidates don’t provide a decent choice for you, you might just be missing the point of representative democracy.
Preferences can be completely bypassed
Preferences are just about the most contentious topic during an election (apart from sailing and speedos, of course). But there are two important things to remember:
Party preferences only apply to the Senate. The whole point of preferences is to save people the bother of numbering more than 50 boxes when they vote. Instead of having to number every box on the Senate form you can just mark a box above the line, and every party or independent candidate can tell the AEC where to allocate the votes if they do not get enough to be elected.
Since you’re supposed to number every box on the House of Representatives ballot anyway, preference deals do not make sense for it.
Party preferences can be completely bypassed by doing it yourself. As I said, the point of preference deals is so that people can vote above the line on the Senate ballot in one shot. More than 90% of Australians do this, so the preference deals that are made are pretty significant. But if you don’t agree with the preferences set by a particular party, you can simply vote below the line and not worry about it at all. Your vote will be distributed only according to the numbers you write down — no-one else has a say in it.
Preferences are actually referred to as “group voting tickets” by the Australian Electoral Comission, who have all the information on the 2010 GVTs. You can also make your own using the nifty tool at belowtheline.org.au and save yourself the trouble of figuring out whether to put Family First above or below the Democratic Labor Party on the day.
Your vote actually does send a message
This one is somewhat more subjective. But it’s something that I have become increasingly aware of recently — as I have been working on this campaign — and perhaps my perspective on this might make someone think that this is a more tangible effect than they previously thought.
I have spent the last three weeks trawling through every little bit of electoral data I can get on the Australian Democrats, particularly how we fared in each electorate — in fact, how we fared at each polling booth — across the state. If I’m doing it, I’m willing to bet that so too are dozens of people for the major parties. I can tell you now, when you spend all your time doing this, you notice everything.
Remember back in 2001 when you decided to put One Nation above Labor, just for a laugh? I promise you that in 2004, someone, somewhere, made a decision based on that action. If only you had known.