Absolutely! In past generations some people were known to have fallen in love by being pen-pals!
Being "in love" essentially is about establishing an "emotional connection" with someone. The only requirement is "communication" between like minded individuals. Once a person feels someone "gets them", shares their same values, and wants the same things as they do oftentimes they'll open up their hearts to them and the possibility of some day having a future together.
Today instead of being "pen pals" and anxiously waiting for the mail man to deliver the next "scented letter" people now have instant messaging, webcams, Skype, email, digital photos, Facebook, cell phones, and text capabilities to further enhance a long distance relationship with someone they've yet to meet in person.