From my own brief experience with long distance relationships (brief because I quickly realized they're retarded) and seeing others engage in them, there are two things done to compensate for the lack of physical proximity.
One is sickeningly effusive expressions of emotion, as if going over the top with the emotional side of things can make up for lacking the physical aspect. Most LDRs I've seen had the people gushing about how much they love each other all the fucking time after like a week of them e-dating. I'm talking over the top levels where if anyone were like that IRL they would immediately be dumped for being clingy and creepy, and then you'd probably want to get a restraining order on them as a preemptive measure against them trying to creeper stalk you and force you to love them. It's awful.
The second thing is the whole gamut of possible sexual activity that can be done between people not in the same room. Talking about sex and sexual preferences, sending dirty pictures, sexting, cybering or sexual roleplay (yes there's a difference) if the pair is down for that, phone sex, and webcam shows (either solo as a treat for the other or at the same time to make it like phone sex with a webcam upgrade). So yeah, there's a bunch of sex-related things that can be done without physical proximity.
EDIT: Oh, wait, were we supposed to give joking responses rather than legit one? Whoops.
