A question we often get when clients are looking to set up a website is what domain should they purchase? A .com.au or a .com?
The main difference between the two is .com.au identifies your website as an Australian Business. This has a number of advantages if you are targeting Australian Internet Users. Search Engines will recognize the location of Internet Searchers and it makes the assumption that if the searcher is located in Australia then Australian businesses are much more relevant and will rank these pages higher then global .com sites.
Another point of difference is to register a .com.au you must have an ABN or ACN to verify you are in fact an Australian Business. Anyone can register a .com without any verification.
What if your market is global? then it may make sense to go for a .com. Having said that it is very common practice for Businesses to purchase both domains and have them both point to the same website. This is perfectly fine, but any more then 2 domains pointing to the same URL is often regarded as spamming by search engines and can reflect negatively on your search engine rank.
The price between the two is marginal, with a .com.au slightly dearer. This is because you are getting the benefit of higher ranking in Australia’s search engine market.