Australia is a very large country with a relatively small population – it is about the same size as the 48 States, which make up the bulk of the USA but has a population half the size of that of California. Vast tracts of the country are virtually uninhabited (and many would say uninhabitable), making Australia one of the most urbanized countries in the world.
The lack of a domestic market of any real size, coupled with a comparative level of geographic isolation, means that Australian businesses increasingly recognize the need to look at international markets to ensure their own future prosperity as well as the future well being of the country. Indeed, a criticism that has been leveled against Australian business organizations has been their slowness to take up the challenge of internationalization (with the notable exception of the mining industry.)
Thus, Australia finds itself needing to become ever more international in its outlook both economically and politically. Their extremely successful economy is dependent upon trade with both the US and increasingly with key Asian countries such as China, Japan, and India. Traditional British Commonwealth links have been declining in importance over several decades.
In short, Australia is a small market with a highly educated, affluent population, which realizes the importance of international trade – they are waiting to do business with you!