Why there is a need of advertisement in present scnerio..?

there is a need of advertisement as to show the consumers what is there in the market. only through advertisements many people are aware what is existing in the market. there are many "free" for products going on. the advertisement helps the seller to attract the consumers ..especially children...advertisement plays a very very important role in selling the products as we have different brands of the same products one can show how better his product is? many of the eatables i feel is running mostly through advertisements..