I disagree even the posting guide lines are pretty clear:
Posting Guidelines
Promoting Work: Only post items that are already available on the Marketplace. Work-in-progress items need to belong in The Work In Progress Forum until they’re readily available for purchase.
#facepalm
He’s not even promoting his own UE4 marketplace asset(I checked Trello there’s no Arteria3D asset), but his very own website you don’t see how that can be slightly wrong? Even if he did have a UE4 asset it still won’t make it right to use space to promote his website sales.