Email marketing is by far the most stable form of marketing online. The reason is that you have the opportunity to connect with people in a structured and automated manner...as well as being able to create long term relationships (perhaps even lifetimes) with your email subscribers.
You may have heard us talk about funnels in the past. This is another name for an email marketing campaign as you are essentially funneling potential customers through a follow-up sequence (a series of emails) to build a relationship within them and in turn, create a customer out of them.
In order to do this, you need to help them. You cannot spam people and expect success.
Here is an example site that utilizes a funnel:
At the bottom of the homepage, you will see the following:
When someone signs up to the form, they are put onto a mailing list. They have essentially granted me access to their personal contact info in exchange for something that I offered, in this case an Internet Marketing Course.
Then, if I am good...I can contact people over and over again, helping them, building a friendship with them, and building trust. Then if I throw in the odd promotion, I can start making sales. This is a great way to market and should definitely be considered.
We also have a Website Builder here within The Open Education Project that you can use to build sites like the one above and easily incorporate an email marketing campaign into.