A new approach is proposed that contemplates systems and methods to enable an individual to complete a financial transaction by swiping a magnetic stripe card through a card reader connected to a mobile device. The size of the card reader is miniaturized to be portable for connection with the mobile device. The card reader is configured to reliably read data encoded in a magnetic strip of the card with minimum error in a single swipe and provide a signal that corresponds to the data read to the mobile device, which then decodes the incoming signal from the card reader and acts as a point-of-sale device to complete the financial transaction. Such an approach enables a person to become either a micro-merchant (payee) or a buyer/customer (payer) without having to purchase expensive card reader devices or software.