Merits and demerits of advertisement?

what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement? what is merits and demerits of posters and advertisement?