What Is the Challenge Presented to Brand Managers by Social

What is the challenge presented to brand managers by social media advertising?

A) Brand managers need to convince social networks to post their ads free of charge.
B) Brand managers need to connect the cost of new social network promotions to the sales they generate.
C) Brand managers need to create "universally appealing" ads as they cannot target specific demographics on social networks.
D) Brand managers have difficulty estimating how many users have clicked on their ads,which leads to problems in assessing an ad's effectiveness.
E) Brand managers need to deal with having only a limited selection of social networking platforms to advertise on.