I don't think that 80% figure is necessarily a negative or unexpected thing. Most people buy phones tied to contracts which come directly from the network. You only really buy an iPhone directly from the Apple Store if you're bringing along your own network or going pay-as-you-go. In terms of incentives, they'd need to make it worth while buying an iPhone directly from Apple. Not just a voucher if you're a student, something for everyone which makes it unique from buying straight on contract.
Also, for store managers to quote "an army of products" is it likely that some Apple executive has bluntly said, "We've got a boat load of new products, so that's something."
Also, for store managers to quote "an army of products" is it likely that some Apple executive has bluntly said, "We've got a boat load of new products, so that's something."