Due to the size of the online trading platform, there may be a limit to the number of strategies that you can have loaded on each account. For example, if you want to run two long trading strategies, you may need two accounts.
Also confirm if you have enough memory on your computer for two or more accounts. CoolTrade allows you to run one long and one short strategy per account. Experienced active traders may run two or more live long and short strategies, while having additional accounts for strategies that they are testing in a simulator mode.
The more robust the automated trading system, the greater the memory requirements. Check this before you sign up or purchase a new computer. If you sign up for more than one account, will your machine have enough RAM to run both or will you need to purchase an extra computer or more memory? If you have a Mac, ask if the software works on Mac, as not all do. You may want to have one computer dedicated only to your automated stock trading programs and run other word processing or spreadsheet programs on a separate computer.