I have just started providing signals on zulu trade and was looking into some other strategies a little bit more. There are often questions on here where newbies ask what broker is best and in essence what makes a good broker.
Something I noticed was the slippage that some broker get away with is just short of theft. This is the current #1 ranked strategy and the average slippage is 4 pips on EURUSD for some of the brokers. Thing is that they are already charging 2 pips on EURUSD which is a joke. On top of that when you want to trade they are filling you another 4 pips through where the market actually is at. This is just absolutely extortionate.
If you trade with an ECN then you should be paying about 0.3-0.5 pips with about that again in slippage (assuming you are not for instance solely news trading). If you had a strategy that made on average 6 pips per trade and you would with some of these bookies be only just breaking even. In actuality 6 pips a trade would make you very very rich.
Anyway, keep this in mind when you are thinking about brokers and especially think about it when your trading live vs. demo. This arbitrary adjustment of the price will burn a hole in your pocket over time.