With Android atleast you can sell the app from your website or any market. With iPhone apps there is no chance of that at all. (Cydia doesn't really count).
Why doesn't Cydia count? I've never understood the logic here. Since the Supreme Court has determined that jailbreaking and alternate markets are legal, what does it matter that Apple would prefer you didn't install it?
But then, I've spent probably 30 bucks and counting on the Cydia store.
The jailbreak ruling wasn't from the Supreme Court, it was from the US copyright office, which found that jailbreaking a smartphone was a legitimate exception to DMCA prohibitions on using technical means to beat copy protection.
The ruling means you can't be sued for jailbreaking. It doesn't give you a constitutional right to an unlocked phone, and it doesn't oblige Apple or AT&T or Google or HTC or whomever to support a jailbroken device. It certainly doesn't impair their ability to use technical measures (aka, fixing bugs) to impair your ability to jailbreak.
Since no one had ever been sued for jailbreaking (and similar policy was not applied to, for instance, the PS3), the practical effect of the copyright ruling was close to nil.
Cydia doesn't count because Apple keeps blocking holes which allow jailbreaking, so with new devices, there can be quite a long time period before you can get back into Cydia.
