Positive:
1.Can make the "subject" become well known among people and thus boost sales.
2.Can establish product image and corporate image
3.Can propagandize new concepts and ideas among the society
Negative:
1.Numerous advertisements in similar style may drive the audience crazy.
2.Overstatement and exaggeration may result in hazardous effects such as safety threats and trust crisis.
3.May cause frauds and briberies in advertisement bidding.