Whatever e-mail server you’re using, they most likely store the addresses to which you have sent or from which you have received e-mail messages. This means that you have at your finger-tips a list of hundreds if not thousands of names of past clients. Some may not have actually done business with you but in that pile of names will be a large percentage of real and potential clients. So what are you waiting for ? Mine that list with regular specials and haven’t-heard-from-you-in-awhile tweaks. Don’t forget that the single best source of future business is existing (or previous) clients. And regular e-mail blasts are one of the least expensive yet most effective marketing tools at your disposal.