So, first off: I really do not believe that this service (Zeusmos) was that popular; I mean, when you hear about the number of people who were using Installous (omg too many ;P), the number of people using Zeusmos would be this tiny tiny speck in comparison.
Once you are only talking about hundreds or even in the low thousands of devices (as opposed to tens of millions), you can satisfy the demand by getting a bunch of friends from your high-school class (the developer of Zeusmos was 15) to register for individual developer accounts and then contribute their Apple ID and passwords to a pool.
Based on what it says in the article (edit: which a friend of mine is telling me might be wrong, so maybe these people are doing something more complex), the other product (Kuaiyong) was using a single Apple Enterprise certificate: you only need one of these to satisfy an infinite number of devices, and they probably were signing the stuff on their server rather than on the client (so not redistributing the certificate).
That said, the rules on how you can use an enterprise distribution certificate are quite strict: you can sign applications used only by 1) employees of your company; 2) customers of your company who are physically present at your company's place of business; or 3) customers of your company who are being physically supervised by an employee of your company while at another location.
Once you are only talking about hundreds or even in the low thousands of devices (as opposed to tens of millions), you can satisfy the demand by getting a bunch of friends from your high-school class (the developer of Zeusmos was 15) to register for individual developer accounts and then contribute their Apple ID and passwords to a pool.
Based on what it says in the article (edit: which a friend of mine is telling me might be wrong, so maybe these people are doing something more complex), the other product (Kuaiyong) was using a single Apple Enterprise certificate: you only need one of these to satisfy an infinite number of devices, and they probably were signing the stuff on their server rather than on the client (so not redistributing the certificate).
That said, the rules on how you can use an enterprise distribution certificate are quite strict: you can sign applications used only by 1) employees of your company; 2) customers of your company who are physically present at your company's place of business; or 3) customers of your company who are being physically supervised by an employee of your company while at another location.