Which should i use blockchain flatform for dApps e- commerce to get 2 criteria : zero fee transaction, instant transfer. Thanks!
You need IOTA, not ethereum.
Ethereum is cheaper and faster than btc in most cases but that's not free neither instant.
IOTA is free and instant, as these are necessary conditions to be used in IoT stuff.
Even assuming that OP doesn't care about using a centralized cryptocurrency, IOTA doesn't support smart contracts yet. So until smart contracts are introduced OP won't be able to use IOTA as platform for their DApp.