A mix of concepts and techniques
The concept of speed and the binomial Fast/Slow are very important in the advertisement's field: these are very useful to underline some aspects of the product. Usually, as we can see in the following examples, slowness is bad, old, passed, while fastness is good, modern, new and technological advanced.
In this spot of Renault Clio the rallenty effect is used to communicate that "slowness is ugly", while the car is very fast (and so this isn't ugly).
This is a very famous 90's spot, directed by Spike Lee for Nike: The rallenty effect underlines the unbelievable capacity of the shoes, that let Jordan to "fly".
This is a spot that takes advantage of speed dating to comunicate the different possibilities of combinations of the product.