Do up a business model, frock up in your best suit, head down to News Corps head office and drop the proposal in front of Rupert. Sounds insane I know, but really that's the kind of corporate muscle it will take to seriously compete with ebay.
I like to call to arms idea on You Tube, and that would absolutely create a ground swell of support, not sure if it would loosen much cash lol, but it's a great way to get the marketing rolling.
You could have sign up pages on MySpace, Facebook, etc, for supports of the cause. Even though people may not want to part with their actual cash to support it, getting their names in support is a serious step forward in showing the popularity of the idea.
Start getting strong support, you can start pushing for media attention, they eat that sort of stuff up!
'People up-rise against ebay!
'A strong ground swell of support is growing among online sellers against ebay for what they consider to be greedy, and unfair business practices being perpetuated against them, and others by the online market giant.
In response to the claims, a spokesman for ebay today said..........
You want to create a cause and raise money, MAKE T-SHIRTS!
Seriously, people in general love a cause, and among online sellers that revolves around bashing ebay to death most of the time lol. Get the merchandise out there for sale.
T-shirts, caps, badges, patches, stickers and so on. Give supporters a reason to support you with cash by way of them receiving something up front for their cash, and they will most likely knock you down to get in line.
I wouldn't worry about leaking any secrets, I would make a plan and yell it to anyone within ear shot, and the net means there are a lot of people in hear shot!