I would highly encourage you to talk to your local small business association, as well as your city officials, before you conclude that it's "worth it".
I'm so sorry for all the small local businesses that can't get any customers from Yelp, internet advertising, advertising on the side of a bus, putting up flyers, having an enticing enough storefront, providing a good enough product/service to get word of mouth, setting up a daily deal, advertising on the radio, or hiring someone to stand by the side of the road with a sandwich board, and have to resort to the frankly sociopathic behavior of wasting valuable time and resources mailing me trash to throw away.