Always use the fee if you send it for no fee your payment can take ages to arrive in the wallet
Thanks for your replies Entz & Newaw.
If I'm accepting 100s of transactions for only 1000 satoshi's, the fee will surpass the whole transaction... correct?
I've read about some gambling sites using their own blockchain or "off-blockchain mode" as they like to call it - what's this mean and how can I achieve it?
You would have to have an internal logging system, which allows users to deposit bitcoins into his/her account, and withdraw it from there.
I really don't see the problem with transaction fees since when the user deposits, the user pays the tx fee, and when the user withdraws, you can just deduct the fee from his/her withdraw amount.