According to industry observers, the turning point will happen when carriers let go of the revenue they currently get from data transfer long enough to allow e-mail to establish itself as a ubiquitous activity everybody uses.
There have been many problems along the way to realising this. For one, carriers seem very reluctant to allow widespread messaging access to their networks without collecting fees from those who send such messages, such as spam. But perhaps the end is in sight for this state of affairs, with carriers being forced to adopt wireless e-mail applications for their own good.
RIM's Blackberry strategy has shown that, despite high costs, e-mail is a feature people want and need. Still, Blackberry is a business-oriented device that not all businesses and few individuals are willing to invest in.
All that e-mail data transfer is pricey. But if money were not an issue, more people would go for it.