Moving into ecom/marketplace

How many Ecom or Market place companies are profitable?

You can start with Amazon Seller Support Associate role. It will give absolutely indepth knowledge about marketplace operations. If you get selected ask to be trained on IIDP/Brand Registry skills this will propell your journey for core marketplace roles later apply for internal transfer in advertising team (tough) and boom you have full package now you can work as Ecom manager for any brand