Coupons Sites - For instance, I have signed up on the mailing lists of Groupon, Amazon Deals and Living Social. All of these companies send me emails featuring great local deals.
In the case of Groupon, I have specified that I am only interested in hearing about restaurants in the city where we live. The company is great and only sends me emails that fit that category. Now, when I see I have an email from Groupon I am anxious to open it because I know it will contain big discounts (usually 50% off) at a local restaurant.