I think that sometimes when someone sees the advertisement they immediately think their life will be better with the thing that they see in the advertisement. And sometimes there are famous people in advertisements and that makes people want the product even more.
An advertisement I think is well done is when it is a bit funny it has a well known person and it is really expensive
I think that what makes it effective are the colors and design you use. You need to use colors that attract people and a design that feels different from other brands and things.