In oasis actives credit they have designed the site to minimize this risk as best as possible.
With regards to oasis active this tradeoff comes in the form of banner ads, fewer features and potentially a lower standard membership base.
Try and look passed the photo and try to read into what people say about themselves with an open mind 'don't be so critical'. Chatting or engaging with people in far away (often exotic) places is only asking for trouble.
If they are locals it is easy to establish their credentials this will minimize the risk of being scammed because believe me they are out there.
There are many very nice, honest, intelligent and successful people out there who could make very good partners with you however may not be as photogenic, poetic or quite frankly as attractive as you would like them to be.
It is very easy to be critical when you're browsing through a long list of profiles but you may be your own worst enemy.