The KISS principle: All business owners face the same initial dilemma: How big should I go? Let me answer that. Did you hear about the KISS principle before? It stands for Keep It Simple, Stupid. Noted by the US Navy in the 60s, it means that you should not overcomplicate the concept. You are going to be in charge of your business in its initial phase, and you don't want to deal with something too big and complicated. You could end with something too elaborated (and probably too expensive) that no one wants or even needs.
Start with something small, and don't let your idea snowball into something too big to handle. Avoid unnecessary costs, especially at the beginning. Remember: Simplicity is the ultimate sophistication. (Leonardo da Vinci).
Lots of successful entrepreneurs got their ideas just by studying what other people were doing and coming up with a way of achieving the same thing in a more simple (and cheap) way.
Brainstorm your main idea, make a list of all possible features/parts/services and then ask yourself the following questions:
* Do I need this?
* Do my potential customers need this?
* Is this crucial for launching my business, or can it wait?
* Can I simplify this?
Then, brainstorm again.