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Jamie is right. You will experience much larger competition in google.com than google.com.au based on the market size alone. Couple this with the fact that your particular industry is also very competitive. Yes, it will probably help to have the .com when trying to rank in google.com but as Jamie rightly states, there are other elements of your SEO strategy that need attention first. As well as your on-page issues, having had a quick look at your backlink profile, I would suggest that you do not have anywhere near enough links to compete with the major players in your market such as cashbackforex.com Adam.