Marry a Stranger Day

Inspired both by kottke's excel love letter and by the troubles to which Joey DeVilla goes when thinking about dumping using PowerPoint, I got to design my own, very practical, logical absolutely impossible way of looking at relationships.
It is all a nice practical approach, with a little bit of misuse of statistics and bad design. I can do those. So, let's proceed:
Since we all know that 50% of first marriages end in divorce, I follows that, all things being equal, the probability of having a marriage that last forever is the same whether I marry the stranger walking down the road or I marry a person that I have known for years on end.
So, for my purposes, it is exactly the same to marry a person I just met. It saves time, effort, money and the end result is pretty much the same.
Of course, the flipside is that I may end marrying a crazy, deranged individual, but then again, what are the probabilities of that happening, when all I asking is somebody that accepts to marry me based on a few minutes acquaintance?