Square — a company best known for the small, white plastic cube that can read credit cards when plugged into a smartphone or tablet — is taking on the likes of Etsy, Amazon, and eBay with the launch of its own online marketplace called Square Market. The expansion from mobile payments to online retail might seem a bit odd to those who don’t follow Square, but it’s part of an ongoing push from the company to deliver a product to answer each aspect of online commerce. In addition to its card reader, Square makes a mobile wallet app for consumers, a payments app for businesses, and a $299 plastic stand that turns iPads into a cash register replacement. It even has an answer to PayPal in the works with Square Cash. “Creating an online marketplace is our next step in making commerce easy for everyone,” said Ajit Varma, Square’s director of discovery.