The answer to this: "The grass is always greener on the other side of the fence."
Think of this from a logical point of view. when you go out in a city, you see the same people over and over again. well, when you go online, tends to be the same situation only different people. I have been on about 5 different sites and found a lot of commonality as to who I see poking around on my profile.
I have pursued guys in other cities before and realized that people you meet online always seem perfect because they write a profile and sometimes have a online personality. You always see those people in a positive light but when you meet them in person, reality hits. Sometimes reality hitting is a good thing because you find out something that interests you further.
I had been talking to a guy for 6 years on and off. I thought he was a great guy and was so excited that we both made the decision to meet and see each other personally. Turns out he is single for a reason, and pulls apart every great guy he meets for some reason. Later I heard though other friends that he was a fair weather vein and looking back things happened exactly that way.
I have met other people i knew online though travel but have not traveled to meet anyone specifically like that person. I am a strong believer that networking with other gay men really helps you meet someone outside the box of the bar fly and the online thing. I still leave the online door open to increase the chance of meeting someone but recognize the online simply as a Masquerade of sorts....
Sometimes that is hot though