Preorder for the Xbox Series X went on sale today, but it may have been the Xbox One X that had the best day in the marketplace.

According to Andrew Alerts, a gaming deal monitor, sales for Microsoft's previous-generation gaming system skyrocketed 747 percent on Amazon. Andrew Alerts speculated that, due to the similarity between the Xbox One X and the Xbox Series X's names, many people accidentally bought the One X thinking it was the Series X.

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The first edition of the Xbox One debuted in 2013. Since then, two enhanced versions were released: the Xbox One S and the Xbox One X. They will be replaced with the Xbox Series X|S, which are expected to hit shelves on Nov. 10 and are currently available for preorder.

Of course, Sony is not standing by idly. The PlayStation 5 will also debut this holiday season, specifically Nov. 12 in North America, Australia, New Zealand, Japan and South Korea, and Nov. 19 for the rest of the world.

Xbox Series X|S will be arriving on Nov. 10 from Microsoft. Preorders are currently available with Series X going for $499 and Series S for $299.

KEEP READING: PlayStation 5 vs. Xbox Series X: Which Is The Better Value?