Jack Shafer in their book "The Like Switch" says that there are 4 elements in building a friendship: proximity, intensity, frequency and duration of interaction

Jack Shafer in their book "The Like Switch" says that there are 4 elements in building a friendship: proximity, intensity, frequency and duration of interaction. Similarly to work and school friends who are very proximal and spend a bit of time with us, online friends tend to be very distant physically but the interactions we have with them can be intense (like gaming) and frequent. So these pseudo-friendships can have some elements of a strong (substitute for the word "real") friendships, but don't have all of them.