Email marketing can be a very effective way of promoting services and products and dramatically increasing sales revenue. When used correctly it is a non invasive marketing tool. The best form of email marketing is derived from opt-in and double opt-in email lists generated by your own website or a related website in your business. Buying millions of emails and sending out a shotgun style email blast is spamming and will not be effective and is now considered a bane of internet advertising - in fact is illegal. Build a solid opt in email list and use it to promote new services and products to people who want or agree to receive these update and it will be effective and successful.