This discussion hits on many of the options in the simple marketing techniques being used in many instances today.
Somewhat missing is emphasis on the human elements and interactivity needed to realize significant gains.
Email blast in many instances is a practice being frowned upon by the DMA and top marketers. Of course, when a prospect or customer is given the ability to opt in with verification, email with appropriate content can be powerful and meaningful.
Meaningful and relevant and responsive use of online approaches can bring customer retention and loyalty. Walk purposefully and focus on the right folks.