There is a reason the Greens get a max 10% of the vote - the ideas that they come up with only take root in that 10% of the population who believes in unicorns and fairies.
From what I have been able to discover about the Watermelon party's supporters, it seems that quite a sizable number are inner city dwellers who are sufficiently well off. They vote for the 'melons' in an attempt to assuage their consciences perhaps?
Others are of course the young radicals/idealists.
One Election day I asked someone handing out the Green how to vote cards about one of their policies. Just received a blank look and a reply that he didn't know they even had a policy on the issue I was enquiring on.