The advantages are:
The products can be known by public easily,
consumer can knowledge about new products,
Can increase the demand

the disadvantages are:
People might misuse the product name,
The advertisement might might give the wrong information.
The price of product have to be increased for advertising cost.

 Following are the merits and demerits of Advertisements:
Merits:
- It helps people in choosing products and satisfying their needs
- It helps in bringing awareness
- Are good source of entertainment
 
Demerits:
- It creates undue hype in people of certain products
- Promotes bad things like smoking, drinking etc
- Can create complexes in people.

 Just like anything there is a good and bad to it.  I kind of enjoy the free promotional apparel some companies hand out however.  They make good gym clothes.