Since it is difficult to measure whether the intention of referred customers is out of doing
a favor for the participants or acting upon their own economic motives, the validity of
referred participant’s true willingness to make the same decision in the real world may
be unclear. In order to address this limitation, it is suggested that more detailed
instruction should be provided in the simulated web site and other validation
approaches such as contacting the participants may be applied. In addition, because the
empirical experiment can only suggest the possible suitable price-network size schedule
in viral marketing, the implications may require further investigation through
mathematical modeling to identify demand curves.