Adobe Digital Insights estimates Thanksgiving to Cyber Monday 5-day period sales at $12.8 billion, up by 15.2% from last year. Black Friday and Cyber Monday both contributed over $3 billion in sales each.

It is hard to estimate how much of that was Amazon sales, but we think it was somewhere in the range of 25-50%. Amazon continues to grow much faster than ecommerce as a whole, and with Prime customer base growing too it is hard to image Amazon not having their best days ever in history during this holiday season.

According to data by Slice Intelligence, which scanned more than 1 million online shopping receipts from Thanksgiving through Cyber Monday, Amazon accounted for 30.9% of sales.

So with $3.2-6.4 billion in sales by Amazon during the holiday weekend, we tried predicting how much of that was marketplace sellers. In Q3 2016 Amazon announced that 50% of sales were from marketplace sellers, however during the 5-day sale Amazon was heavily promoting their own line of products like the Amazon Echo devices.

Nonetheless, all things considered we think it is safe to assume at least $1 billion in sales was from marketplace sellers.

It might have been even more. It’s unlikely for Amazon to release any specific numbers, so all we can do is guess. Either way it shows how important the holiday season is, the sort of scale it reaches and how key it is to have enough stock to not to miss out.