Does anyone know how to run a legitimate competition. I am in Australia, but the majority of entrants would be in the US, EU and worldwide. Is there anything i have to comply with ? I really want to make it look and be legit, to gain users trust. Any suggestions ?
That depends on what you are offering. When I run a contest on my sites, I always through in the usual legalese such as "void where expressly prohibited by law" and the such. I am based in the US, so I often will limit my participants to a small geographical area especially when something must be shipped out. Also, check Australian law to see if there is anything in your country that would prohibit the running of contests. Maybe a tax or a free would be incurred too.
If you live in Australia I dont think you need to worry about the US government coming after you holding a contest Unless it's illegal in your country, no other countries would have jurisdiction over the matter.