Many people avoid email marketing in the mistaken belief nobody reads it and that everything gets classified as SPAM.  Nothing could be further from the truth and it is an absolute mainstay of successful small business websites the fact that they have successful email marketing campaigns to "remind" people the business exists.

Ethical email marketing - which relies on you knowing who you are emailing, and the person being mailed giving you their consent to do so (and also allowing them to opt-out) is not SPAM. It is very effective marketing and you should not feel embarrassed to make use of it.

Ethical email marketing allows you to leverage technology for what it is good at - to be able to produce high quality, arresting messages and communicate them in large numbers and track the results.

I have used ethical eMail marketing to great effect for clients where it has been necessary to keep the company concerned "in front" of their suppliers and potential customers over an extended period of time. A monthly newsletter sounds a bit cliché, but the webstats are testament to their effect of "reminding" people the particular client exists.

Fact: for Hotels and Accommodation email marketing is now THE marketing method of choice.)

Email Marketing can be broadly or narrowly defined:

From simple emails with your news to graphic newsletters created by a software package like g-mail or Constant Contact.

On the more CRM-driven side, there are services such as Infusionsoft which actively follow-up contacts with subsequent product offers (e.g. "Now accessorise your recent purchase with the following items...")

List building services include Aweber.com