But someone say to me that I can
delivery to a infinite number of
iphone without using the app store. Is
it possible?
Yes. The whole point of the enterprise developer program is that it lets large organizations distribute in-house apps without having to go through the App Store. You're not limited in the number of devices that you can distribute to. However, you should read the enterprise program license carefully -- I believe it contains terms that say, essentially, that you're only allowed to distribute within your organization. That is, you can't get an enterprise license and then start distributing your apps publicly.