There are many online wallets like Xapo and Coinbase that do not charge any transaction fees or they pay that fees by themselves. I want to know that how would they profit from paying for their user's transaction fees ?
If no fees is charged then the transaction take a much long time or even might get cancelled !
Both Xapo and Coinbase are not just online wallets (which cover the transaction fee), they also have the exchange section on their website, so coinbase charge 1% on exchange. Xapo has their own bitcoin debit card and they also charge fees to use their card.