Argument quality has a positive effect on the product usefulness evaluation. The quality of arguments contained within
persuasive information determines the degree of informational influence when a person cognitively elaborates on persuasive
information (Petty and Cacioppo, 1986). Consumers need to cognitively elaborate information which comes from C2C communications
to help them make task-related decisions. That is, argument quality is an important central cue for consumers
evaluating the usefulness of a product regardless of whether communication information comes from real or virtual relationships.
Hence, argument quality positively influences the product usefulness evaluation of consumers in the C2C communication
contexts.
Source credibility has a positive effect on the product usefulness evaluation. Consumers communicate with others in a
one – to – many or many – to – many relationships in online communities. As people are different in product knowledge
level, product information from those who are perceived to be believable, competent, and trustworthy will be considered
more effective in evaluating the usefulness of the product. That is, source credibility is an important peripheral cue for consumers
evaluating the usefulness of a product regardless of whether they have real or virtual relationships with the sources.
Hence, source credibility positively influences the product usefulness evaluation of consumers in the C2C communication
contexts.
Contrary to expectation, tie strength exerts a significant effect on product usefulness evaluation when consumers mainly
communicate with virtual relationships but none when they mainly communicate with real relationships. One possibility is
that ‘‘water army’’ (a group of Internet ghostwriters paid to post online comments with particular content) widely exists
when consumers communicate with virtual relationships. Given that members typically do not know each other personally
in online communities with virtual relationships, consumers may worry about interferential information from a ‘‘water
army’’. To a certain extent, tie strength can help consumers recognize the identity of communicators when they communicate
with virtual relationships, and thus tie strength serves as a significant peripheral cue in the online virtual relationship
contexts. On the contrary, members typically know each other personally when they communicate with real relationships.
Consumers do not need to worry about disturbances from a ‘‘water army’’. In addition, consumers choose to communicate
with acquaintances in online communities rather than directly communicating with offline strong ties maybe because strong
ties cannot solve their problems. They want to hear thoughts from weak ties, too. Thus, they accept effective product information
and shopping advices from both strong and weak ties. That is, tie strength is not a significant peripheral cue in the
online real relationship contexts.