A little over fifty years ago, this technology was revolutionary in the temples of the money changers.
http://en.wikipedia.org/wiki/Magnetic_ink_character_recognition
Magnetic ink character recognition, or MICR, is a character recognition technology used primarily by the banking industry to facilitate the processing and clearance of cheques and other document. The MICR encoding, called the MICR line, is located at the bottom of a cheque or other voucher and typically includes the document type indicator, bank code, bank account number, cheque number and the amount, plus some control indicator. The technology allows MICR readers to scan and read the information directly into a data collection device. Unlike barcodes or similar technologies, MICR characters can be easily read by humans. The MICR E-13B font has been adopted as the international standard in ISO 1004:1995,[1] but the CMC-7 font is widely used in Europe.
Otherwise known as the ABA Routing Number. If you have a recurring bill that you want to have automatically deducted from your checking account, this is the number that they use.
Until very recently, the technology that read/sensed these numbers was not commonly found at merchants. Banks had it, hastening the process of clearing checks once they were deposited.