One of the greatest advantages of email marketing is that it allows marketers to send targeted messages. Print, radio and television ads are broadcast indiscriminately and frequently reach consumers who have no interest in the product offered. But email marketing allows companies to tailor certain ads to certain customers. If a customer has shopped for a brand of shoes in the past, companies can email them coupons for that same brand knowing that they have already expressed an interest. Companies can elect to manage their own email marketing campaigns or they can choose from over 1000 different companies who offer email marketing services. These services provide easy software tools that allow companies to manage their email lists, design ads, and track how often they are accessed. Larger companies that send out dozens of daily emails to tens of thousands of different customers often use email marketing services to manage the process.