Once the merchant has the customer's email address, they can send them special offers, inform them of upcoming sales or events, offer to enroll them in a loyalty program, and more. What might otherwise have been a one-time transaction becomes an ongoing relationship and an opportunity to gain entirely new customers. The SAIL mobile app is also capable of reading barcodes, which will make it easy for merchants to redeem coupons and fulfill other types of offers.

The SAIL app for iOS devices will be available for download from the Apple App Store tomorrow. An Android version will be available later this month. Merchants who for the service (by providing their contact information, Social Security number, and a bank account) will be able to accept payments via American Express, Discover, MasterCard, and Visa almost immediately (following a "soft" credit inquiry that doesn't affect an individual's credit score).