1. I can easily find a market of hungry buyers online that want what I have
2. I can get to these hungry buyers via Google AdWords
3. I do not need to be first to market to succeed
4. I can grow slowly and still be successful
5. My solution does not require integration with major industry players to be viable... if integrated it’s a bonus but not a requirement
6. I have found several end users who have agreed to buy what I am selling and secured money from them before building my product or solution (proves idea relevancy)
7. If I'm not number one or two in the market place I could still be a raging success (i.e. after Facebook and MySpace is there really much room left? Does anyone really need another similar Social Media solution? And how much money would it take to compete?)
Not all ideas are good ones. Not everyone wants what you think they will want. No one buys for logical reasons... buying decisions are based on emotion and later justified with logic (if possible).
Be sure before you invest your time and money that there is a market for what you are building. It will save you a tremendous amount of pain and debt.
Thanks to Google AdWords it isn't that hard to test an idea and prove concept before committing.