@Flexicon,
In the vast majority of cases it's not, but it depends on the two people involved. My sister who lived in Australia, married an American. They'd only known each other for a month before he went back to the US. Ie. sometimes it works.
By the way - in terms of risk : if you are talking financial risks, then you want to be VERY certain that not only is he/she the one for you, but that you are the one for him/her. Financial risks can affect the rest of your life, while having your heart broken won't.
Are both of you capable of staying interested in each other over a long distance relationship? (if it's to work, then the answer should very easily be a 'yes'...uncertainty usually means 'no')