I want to sell online with an already stocked web store..I'm just not sure if they are scams or if it really w

I found some website that will offer you electronics for you to sell..its already stocked and all you have to do is design your webstore and mannage it. Do they really work and produce money for your self...Has anyone done this before? Which is the best to join? I want to consider but dont want to get into no scams.