They are trying their flirting skills, and how effective they can be. Then, they use this knowledge to the women at their local bar/yoga class/church/wherever. No serious person would want to commit spending the rest of their lives with someone they've never met.
A nice strategy would be to make sure your every email inspires the guy to give you some sort of reply... something like The Arabian Nights/The 1001 Nights
Your boyfriend/girlfriend will be moving far far away for work. You...
If I had to change a continent every time I wanted to break up, I'd be faster than Phileas Fogg