A whitepaper from Adobe, “The ROI from Marketing to Existing Online Customers,” states that rehash customers tend to purchase more than first-time customers do. A newsletter campaign is a simple way to communicate with a client, but the Ask reorder to your client will be more captivating than a bulletin campaign. Scheduled Email and SMS: Not only email but SMS the mission as well, which has a high open rate. For more deals, use both email and SMS to reach out to your clients.