Perhaps they wouldn't want to lose out on the revenue but since this amount of money would get a good deal of press maybe Google would consider doing the ads at a discount or pro bono. It seems like the kind of thing Google would be in to. If and when the Facebook group gets decently big (25k?) we could inquire about that possibility.
50,000 users would surely count as a critical mass, meaning that each member of the Facebook page effectively created $20,000 for charity.
This also means that each new member you recruit is like creating $20k for charity. Worth mentioning that on the Facebook page.
Recruiting support for causes is usually a lot easier if you can say in concrete terms what the cause will accomplish. Maybe 1 billion is a big enough number that it doesn't matter but I suspect being able to say things like "Will feed 100,000 children" or "Cure disease x" helps charities get support.
Maybe we could some of the copy could say things like: "If 1 Million Dollars will feed 100,000 starving children... imagine what 1 billion dollars could do." Better yet if they are things that have actually been accomplished. So "If $23 Million a year erradicated smallpox, imagine what $200 Million a year could do." Etc. You could do 3-4 of these. That way you give a sense of the kinds of things that their participation could lead to without having to know exactly how the money will be spent.
Also, since it is starting with a facebook page, make sure to check out Facebook's advertising options if you haven't yet.
Edit: Is there any particular way I can help you with this. I'm a broke college student so I can give a little money for ads but if there is anyway you can use my time, I'm in.
It's unlikely that the revenue figures would be so high. You can't plan with 100% confidence on high-end estimates. People may not want to click banner ads from craiglist resulting in low revenue.
We can reasonably debate torture vs. dust specks when it is one person being tortured versus 3^^^3 people being subjected to motes of dust.
However, there should be little debate when we are comparing the torture of one person to the minimal suffering of a mere millions of people. I propose a way to generate approximately one billion dollars for charity over five years: The Craigslist Revolution.
In 2006, Craigslist's CEO Jim Buckmaster said that if enough users told them to "raise revenue and plow it into charity" that they would consider doing it. I have more recently emailed Craig Newmark and he indicated that they remain receptive to the idea if that's what the users want.
A simple text advertising banner at the top of the Craigslist home or listing pages would generate enormous amounts of revenue. They could put a large "X" next to the ad, allowing you to permanently close it. There seems to be little objection to this idea. The optional banner is harmless, and a billion dollars could be enough to dramatically improve the lives of millions or make a serious impact in the causes we take seriously around here. As a moral calculus, the decision seems a no brainer. It's possible that some or many dollars would support bad charities, but the marginal impact of supporting some truly good charities makes the whole thing worthwhile.
I don't have access to Craigslist's detailed traffic data, but I think one billion USD over five years is a reasonable estimate for a single optional banner ad. With 20 billion pageviews a month, a Google Adwords banner would bring in about 200 million dollars a year. Over five years that will be well over a billion dollars. With employees selling the advertising rather than Google, that number could very well be multiplied. An extremely low bound for the amount of additional revenue that could be trivially generated over five years would be 100 million.
I'm very open to other ideas, but I think the best way to assemble a critical mass of Craigslist users is via a Facebook fan page. Facebook makes it very easy to advertise Facebook pages so we can do viral marketing as well as paying Facebook to direct people to our page.
50,000 users would surely count as a critical mass, meaning that each member of the Facebook page effectively created $20,000 for charity. I don't think there has been any time in history where a single click had the potential to do so much good, and the disbelief that this is possible is the main thing that our viral campaign would have to overcome. After the Facebook fan page got beyond a certain number of users, we could more aggressively take the campaign to Twitter and email.
Are there any social media marketers in the house? The first step is deciding what to call the Facebook page; it's limited to 75 characters.
It's time to shut up and multiply. I will match the first $250 donated towards the advertising budget for this, more next month depending on my personal finances. If anyone independently wealthy is reading this, $20,000 is probably enough to get the critical mass of users this week.
I welcome all of your criticism, especially as far as the mechanics of actually making this happen. As far as how to optimally distribute money to charity, that is very much an unsolved problem, but I think it's one that we can mostly worry about when we get that far. I also expect Craig and Jim to take a leadership roll as far as the distribution of the money goes.
Also see previous discussion.