For example when an individual purchases an Apple product (like an iPod), unless something goes physically wrong with it, their direct experience with the brand is a one-off. All further brand development (for the customer) is in majority a by-product of their interaction with the end-product (which in the case of an iPod is v.good).

With brands like Verizon, BT, Virgin Media, Orange, etc an individuals direct interaction with the brand is multi-faceted. Impressions are generated from not just the end-product, but customer service (bills etc), effective price changes, quality of service, etc. This, if the average quality is not up to standard, can have a serious adverse effect on a customers brand loyalty. Hence the reason why companies (such as Apple) more often than not have a much stronger sense of brand loyalty from their customers than many other major brands.