Posting stickers is one of the first urban art forms. We have been posting stickers professionally since the beginning. Advertising stickers are highly targetable and be can place them exactly where your young customers are. Considered a lifestyle marketing tactic, we place them alone of in groups and sometimes we ill hand write messages on the stickers to delver a more personal message. Sticker tagging is great for all kinds of clients. I would use stickers in locations where I know that my target is all the time such as a bar, skate shop, or music venue. Posting stickers for advertising should only be done by responsible suppliers who know what kind of material and adhesive to use to get the most out of the sticker but not damage the property that it is adhered to.