During the later stages of the decision process, expertise of the
source will only exert influence to the extent that it affects either the
perceived costs or benefits of the recommended product or service. If
the recipient can easily assess these costs and benefits without
ambiguity and with full confidence, source expertise should bear no
influence. On the other hand, when a product or service is complex,
when its benefits are not immediately observable, or when the
benefits are ambiguous or intangible, recipients of the WOM
communication may rely on the expert opinion of the source as a
cue for whether to showproduct or service interest, and for evaluating
and potentially purchasing the product or service (Rogers, 1995). This
argument aligns with Robertson (1971), who maintains that products
high in complexity and perceived risk and low in testability are more
susceptible to personal influences than those low in complexity and
perceived risk but high in testability.
On the other hand, in the absence of such complexity, recipients
will not need to use the source's expert opinion as a surrogate for their
own judgment.
We next present a field study in which we are able to empirically
test this model.