Every Gloriads blog article tagged Merch on Demand.

An Italian Merch on Demand creator with a partita IVA in the ordinary scheme can deduct the 22% VAT on Amazon ads. Why, and what it costs.

Sponsored Products and Display ads stop on their own when a product is out of stock; Sponsored Brands keeps spending. For FBA, FBM, KDP, Merch and vendors.

Without a VAT number, a UK Merch on Demand designer pays 20% VAT on Amazon ads and never gets it back. Registering voluntarily lets you reclaim it.

US Merch on Demand designers pay no VAT on Amazon ads. Only Washington adds sales tax, 7.6% to 10.7%, not reclaimable. A legal way to pay it on far less.
Gloriads runs your Amazon Ads by rules you control, on all four ad types.