A lot of people collect things and that is why collectible toys in childhood are so popular. Having a collection becomes an achievement and a talking point. The collection leads to discussion and decision making. When a child chooses a toy for their collection they are sub-consciously making lots of decisions about which one to choose. They help communication, verbal skills, sharing and role play.
A set of toys gives comfort and the opportunity to play alone or with others. Collectibles can be vehicles or characters and so are gender neutral. They can be interchanged with other collections increasing the possibilities for play and story telling. Playsets allow children to discover other worlds whether real or imaginary.