Animated gifs in email are a means to grab reader attention and to more effectively promote an offer or product without raising issues and costs associated with embedded video.
Animated gifs are supported by allmost all email clients and services. When animated gif is not supported, only the first frame (image) is displayed. Of course, animated gif can’t be seen when images are blocked by email clients.
Animated gifs are more an alternative than a substitute to video in email because the animation is shorter and less evolved.
Some email case studies with animated gifs and good creative ideas have shown spectacular lift in responses (clicks or conversions).