I agree with Sarahsweets. Strictly online relationships do not allow you to see the whole person in their entirety. And that can be a vastly different experience than what one experiences online or long distance without ever having met.

I had a long distance online relationship that felt like true love for the first 6 months while we were distant and online. Then we moved in together, and I saw all of him, the good, the bad and the ugly and the ugly was really ugly. It became a total nightmare for me and eventually, I had to kick him out. He had hidden many parts of himself from me while we were strictly online and long distance - things I never knew and never saw came out while we lived together.

So, sure you can fall "in love" without seeing the person yet, sure that's feasible. But you cannot fully know someone inside and out until you've seen them in person and not until you've lived with them.