These days the debate over direct mail versus email seems to be over. The conventional wisdom is that direct mail is too expensive and takes too long. If a retailer has had bad sales over the weekend, they want to take action now and not wait a month or two to get a direct mail piece delivered to their customers’ mailboxes.
However, this approach could ignore some valuable customers. What about your customers who are not emailable either because you don’t have their email address or they have opted out of email communications? Also, sending an email doesn’t mean it will actually be seen by the consumer. Google’s use of the promotion inbox makes it easier for consumers to ignore marketing communications. In addition, plenty of people have secondary email addresses that they use just for these types of communications and which they check only rarely.
In addition, there is the question of whether email is always the best channel for the message. A recent study found that physical ads were better than digital ads in some respects. See here: http://www.dmnews.com/postal/direct-mail-has-a-greater-effect-on-purchase-than-digital-ads/article/423292/
In the end, it may be a multichannel strategy that works best for you. Through a test and learn approach you can determine what generates the best return on your marketing investment.