Mining nodes are incentivised to store your new transactions not just because they receive newly minted coins, but because of the amount of transaction fees you bid for your transaction.
If you are transferring from an exchange or a wallet, it will almost surely adjust these fees for you, but if you somehow transfer coins without paying a transaction fee, they will get stuck in limbo since mining nodes will have no incentive to include your free transaction over all of the paying ones. You can use more advanced wallets to transfer with higher fees if it is urgent and you want to have higher likelihood of your transaction going through in the next 10 minutes on the next block.
Currently (9 Oct 2017), if you look at http://bitcoinfees.21.co/ , you will see that you must pay at least 150 satoshis per byte to gurantee your transaction on the next block. If you pay more than that, you are likely wasting money. This is a great website to bookmark if you are using Bitcoin to pay for things often and ready to move to the next level of sophistication.