Impact of social media on online marketing and consumer decision

Explain three gaps of using social media on online marketing. 1st gap, Trust between consumer and brands (1000 words and more). 2nd gap, identifying right platform and right audience (1000 words and more). 3rd gap, Budget (1000 word) * for each gap 5 references 2) Practical cases of using social media on online marketing in a business approach and how it impact at customer decision. Then a comparison between those models of social media platforms used on online marketing. (in total around 4000 words)