Online business is about passing traffic from website to website. It is one of the reason why YouTube was acquired! Example of how AirAsia expands and monetizes from their traffic (ignore sequence)!
AirAsia -> Snack Attack -> GoInsure -> Xpress Boarding -> AirAsia X -> AirAsia Games -> Tune Money -> Tune Hotels -> ??
a4trip -> asiatrip -> a4guide -> a4frens -> a4manager -> .. a4apple? :)
To make it happens, the first one must be the first and most successful one!