Apple supports three app deployment methods.
B2C - aka - the normal app store
B2B - this looks and acts like the normal app store but the app is not visible to the general public.
The only way to get an app to someone is via invitation using a redemption code. This looks to the user like a hybrid of a gift card redemption and a link to an app in the app store.
For this you "purchase" (they can be free) a set of redemption codes from Apple. They send them to you in a spreadsheet. You are then responsible for distributing the codes and tracking which have been used. Apple will send a report of those that were successfully redeemed.
This method can only be used if the app meets Apples criteria for B2B. If they feel it is something that could be on the general app store that is where they expect it to be. The sticking points are really around functionality that can only be used by your business partners, no redeeming public value.
This is also a valuable in ensuring that you don't have an app that gets poor reviews by people that can't use it because it is only useful to your partners.
B2A - aka Enterprise Deployment. This is a special and seperate development account that allows you to host an internal app store and package your own applications for in house deployment. Apple will only allow companies that meet certain requirements to have this type of account. There are strict rules around the deployment as well. Apps may only be distributed to employee devices and are not allowed to be distributed to non employees/customers/business partners.
