(CNN) -- Sure, lots of folks might be excited about a Twitter-like social network with no ads or annoying "promoted tweets." But would they pay for it? The founders of App.net think so, and so far they've found more than 10,000 people who agree with them. The startup promises a "real-time feed" that will never be supported by ads. Instead, they'll charge a fee that, at least for now, looks to be about $50. That's how much it took to support a Kickstarter-like fundraising campaign that has netted more than $670,000 and wraps up Monday. Founder and CEO Dalton Caldwell says he's been disappointed by the advertising models of sites like Twitter and Facebook and thinks users will be willing to plunk down money for an alternative.
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App.net plans to offer an ad-free alternative to Twitter, but users will have to pay
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A Kickstarter-like fundraiser generated more than $670,000 to start up
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Charging fees lets the service focus on users, not advertisers, founder says
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Minimum donation was $50, but analyst predicts that will get lower
Facebook
The multibillion-dollar profits of @placeholder come primarly from advertising, leading to a commonly repeated line that Caldwell appears to echo: "If you're not paying for a service, you're not the customer -- you're the product."
Twitter
Twitter
Twitter
Avoiding ads and opening the service up to developers could offer a glimpse at what @placeholder could have become if its creators took a different path, he said.
Twitter
Twitter
Twitter
But when @placeholder started, I don't think anyone knew there was a business there either.
App.net
App.net
@placeholder is currently open in an early "alpha" version for donors.