In cyberspace, most of the time all you really experience is the other person's mind, and not their physical qualities. So perhaps Platonic loves are more likely to occur. They may HAVE to meet each other for the relationship to fully develop and to be fully satisfying. For these people, the internet simply was a way to meet each other. The couple may be collaborating in the creation of a mutually satisfying fantasy that portrays themselves in ways very different from how they truly are in reality.
Many people allow themselves the luxury of fantasy - either through books, or TV, or movies.
And most people don't confuse this fantasy with reality. I think the internet is having a major impact on how people will relate to each other. As I see it, cyberspace relationships will evolve in two distinct directions. Through the computer, you will see and hear the other person almost as if they are in the room with you. In the second, and more fascinating scenario, people will interact with each other in more sophisticated imaginary worlds and with imaginary identities.