Most traders would agree that they'd like to "test drive" a system before using it. Some programs allow this through "back-testing," in which the program uses historical data to execute the trades and show you what they would have been.
This is not always accurate, as there is much data needed to perform a thorough back-test and it's nearly impossible to replicate all the circumstances with just the historical data. In addition, how the system performed in a market last month or last year does not indicate how it will perform in the here and now. The best automated trading software will let you practice stock trading using a live real-time data feed during market hours. This is the preferred method, as it gives traders a very realistic view of how their trading strategy is performing and the ability to feel the highs and lows of daily trading without investing real money. If you can simulate trades, you won't need to open an actual brokerage account until you go "live" with real money. Ask if there is a limit on how long you can run in the simulation mode.
One of the highlights of CoolTrade is its ability to simulate strategies in real time indefinitely before you run them live. CoolTrade has its own data feed, which allows you to run the strategies in a simulator mode. You should also review the size of the trading lots—are they 100 shares or 1000 shares? When you see how the strategy is performing, you can make changes or determine which broker is best to use, based in part, on the size of your trades.
This feature is indispensible, as traders who value their money rarely run a strategy without testing it first.