I look at it as a way to get noticed. You'd be free to unfollow as soon as they zap you. Maybe some do that. Maybe some don't. Maybe some check the feed out and decide to stick around.
Discussion
I agree that it’s a way to get noticed. On one hand, some follow and stick around, some follow and unfollow as soon as they get zapped. Some also see the zap 4 follow and steer clear because it’s spammy/fake engagement.