Netflix's DVD model worked because everybody was used to renting movies from Blockbuster. The business model already existed: Netflix just did a better job of it and at exactly the right time. Will you have to change hearts and minds, or will you be simply "doing a better job than Blockbuster"?
It seems like you're considering some business that requires a lot of inventory, low margins, and high-operational costs. I guess I'm making a lot of assumptions.
EDIT: I guess I sound fairly negative. I'd like to add that I have a dear friend who manages to earn a decent living with a small internet-based video game rental service. It's a husband/wife team. They somehow managed to bootstrap the business, earn a loyal customer base, and maintain inventory in their apartment. They spend a few hours per day manually fulfilling orders, adding custom notes/suggestions to their customers, etc. It works quite well for them.
If your idea is in fact without competition then include who are possible competitors no matter how slight. To not have any competition is a HUGE red flag. By including even the slightest of competition then you are showing that you have done your research. Also, make sure you have a rock solid way of explaining how long it will take for investors to get their money back.
Contact your group of contacts and ask them why they do not want to back you. You may be surprised at their responses. But take their advice and alleviate their concerns. Because their concerns will be the same as potential investors.
Find a way of doing it on a smaller scale that you can afford to finance yourself. You will need a proof of concept anyway so start working on that. People are more likely to invest in things they can actually see not ideas alone.