The announcement marks a significant retail expansion for the device, which is already available at Target, RadioShack, Best Buy and approximately 200 Apple stores. Wal-Mart will bring its retail outlet total to more than 9,000.
The card reader itself, which plugs into the headphone jack of iPhone, iPad and a variety of Android devices, can be ordered for free at squareup.com or for $9.99 in stores. Those who purchase the device in stores can apply for a refund from Square online.
The low cost of entry has been effective in reaching the hands of Square's target customers: small business owners who can't afford to invest in credit card terminals. Some 800,000 devices have been shipped to merchants thus far, according to Bloomberg. The startup, which is now processing more than $2 billion in credit and debit card payments per annum, takes a 2.75% cut on all transactions.