Microsoft today announced another expansion of its retail store efforts, this time to the popular e-shopping site eBay. The new Microsoft Store on eBay is open for customers in the United States, providing eBay's 124 million active users with access to the firm's first-party hardware and software.

"We are excited to work with eBay to help expand our retail footprint and give even more customers another complimentary, convenient and safe online shopping destination to purchase their favorite Microsoft first-party products, just in time for the busy holiday shopping season," Microsoft vice president Kevin Eagan notes in a new post to the Official Microsoft Blog.

While it's not clear exactly what's different between the standalone Microsoft Store online and the eBay version, Microsoft notes that both offer the same free ground shipping, return policies, and even access to refurbished Surface tablets and other devices.

That said, I noticed that while the Microsoft Store online is offering various versions of the Surface RT for $299 and up, the eBay version of the store only offers the 64 GB version for $339. (The price is the same between both stores.)

In addition to its online storefronts, Microsoft now offers 81 full and specialty retail stores and as I first revealed earlier this year, it's now got numerous store-within-a-store locations at Best Buy and other electronics retailers around the world.