Amazon app is one the best site for selling online product but I see that many following parts which is not good for user
1) take shipping charges many
For many products take much shipping charges so customer get it product effectively more costly then market rate so not choose for small thing
2) for replacement it process is more complicated than other also take proof which is not take care whenever product they deliver
3) Not give shipping charges back where we request for refund for deeffective product so that we give with out any product pay shipping charges
4) not give good offer and also usefull sell for customer
But Amazon certified user( full wright) product qulity is so good and new technology device is available on this app.