An advantage of social network advertising over traditional advertising media is: it is cost-effective when compared to traditional advertising media ads can be targeted to reach people with the desired demographic characteristics advertisers can quickly change the advertising message when required ad viewers can easily identify useful contacts a. it is cost-effective when compared to traditional advertising media b. ads can be targeted to reach people with the desired demographic characteristics c. advertisers can quickly change the advertising message when required d. ad viewers can easily identify useful contacts.