title: Preferential exchange: strengthening connections in complex networks.
authors.affiliation: INFM UdR ROMA1, Dipartimento Fisica, Università di Roma La Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Caldarelli
authors.forename: F
authors.initials: F
authors.lastname: Coccetti
authors.forename: P
authors.initials: P
authors.lastname: De Los Rios