Mainly, the hackers crack iOS “just for fun” and do not aim to get any lucre (when their material support is already secured in other ways). But sometimes there is a big customer who can pay much money for the information on exploits of mobile operational system from Apple. Zerodium company is an example of such customers.
This company has paid one million dollars a group of hackers for creation of unbound jailbreak which can crack iOS remotely, without the user intervention. To say in other words, a simple visiting of a web page in Safari, instead of installing third-parties apps and updating the device would be enough.
Wired edition informs that not iOS 9.0 or 9.0.2, but iOS 9.1 and beta-version of iOS 9.2 were tested at the experiment. So it appears that Zerodium got the unique list of vulnerabilities for cracking the operational system. Nevertheless, the experts of the company consider iOS to the most protected mobile OS in the world.
Zerodium specializes in earlier unknown exploits and loopholes. That is why the compensation of hackers was so high. We can only hope that the company will inform Apple on detected vulnerabilities and will not use them for own lucrative purposes.