I'd still be interested to know the motivation for their process. If someone made a firm offer of $450K, it doesn't make any sense to shut down the service just because they didn't meet the $480K requirement. That would flush $450K down the toilet. The obvious solution is an auction, not an ultimatum.

I'm generally a defender of 37signals' methods, but it seems they didn't think this one through. They're lucky they found a buyer—it saved them a lot of embarrassment.