There are several reasons why short promotional videos are important on social networks: 

1. They convey more information: short promotional videos convey information in a very minimal amount of time. They are very targeted and help to better present a product or service, as the use and benefits of the product can be shown through a visual. 
2. Short promotional videos are usually attractive and interesting, which can attract more people’s attention, increasing the effectiveness of the advertisement. They also help to create an emotional connection with the customer, as emotions and feelings can be conveyed through a visual advertisement. 
3. They can be easily shared: on social networks, short promotional videos can easily spread among the community, reaching more users and expanding the audience. 
4. They can attract attention: short video advertisements must be very interesting and attention-grabbing, encouraging users to purchase products or the advertised service.