@ResonantInfinity I think your numbers are quite accurate! Except for the number of creators, which is much higher. Many creators do not have 7 products.
I found a blog post on the unrealengine.com site: Epic Announces Unreal Engine Marketplace 88% / 12% Revenue Share - Unreal Engine Its dated juli 11 2018 and they share the following numbers:
1500 marketplace creators offering 5000 products. (juli 2018 ! )
They also state that between 2014 and 2018 there have been 8 million downloads. I’m not sure if these are sells or each download counted? And free items ensures a massive increase of downloads.