The third big turtle of e-marketing is retention. It's well known that it costs 10 times more to acquire a new customer than to retain the ones you have, so retention becomes a very important objective of your marketing program. Take that opt-in house list of people who signed up for promotional and/or informative emails, and contact them on a consistent, periodic basis. And remember to make a distinction between the two. Send promotional emails describing sales and specials to those who signed up for that, and informative email newsletters to those who signed up for information about your product or market niche. Don't do a bait-and-switch on your subscribers. If you do, you'll find that your opt-in house list will shrink considerably when your subscribers hit the unsubscribe button.
Another retention strategy is to create a discussion board on your web site for your customers and visitors to interact with each other. If you maintain good discussion boards or forums and participate in them yourself, you'll find that these can be a valuable customer-retention tool, in addition to acquiring some great feedback on your product or service and how your business is perceived by customers and visitors to your site. Along these lines, consider providing some special knowledge about the product or service niche that you serve by establishing an "Ask the Expert" board, where customers and visitors alike can ask specific questions of your expert staff on your products, service, and industryand receive answers.