In order to 1-stand out from the crowd and 2-brand your name as innovative, imaginative and exciting, you have to really put thought into your merchandising. Snopes has a beautiful representation of bagvertisements that have been virally making the internet rounds via passionate email forwarders.
Retailers long ago learned the value of promoting themselves by ensuring that the bags they gave out to customers to take purchases home had their store’s name and logo emblazoned on them. Likewise, manufacturers have caught on to the value of buying advertising space on shopping bags and creating specialized bags to promote their own products. As expected, a good deal of creative effort now goes into trying to make such advertisements as eye-catchingly memorable as possible, a process colloquially dubbed “bagvertising.”
My only observation here would be that smart companies will need to actually write their name or url or some identifier on the bag to take advantage of all that great (and free) viral advertising. Shocking people on the street and via email with your cleverness is useless if we don’t know who’s responsible.