Creating a newsletter has many, many advantages. You'll be able to follow-up on current customers but also get potential customers interested and kick them off the fence.
So in other words, it promotes your business and help you sell more and more products because of the trust relation you are building up.
What you should write about
What you actually put in your newsletter should be substantial enough to draw more readers to you who might be your future buyers.
What you write about in, e.g. articles, promotions, etc, should be interesting and informative without getting boring or hyping things up too much. It's important you add your own personality into the mix. This will help you boost the response on whatever you write.
If have a bunch of stuff to sell, tell them about that new product, or discount on old ones or simply send them some solid information to keep them interested.
How to design a newsletter
You have to avoid making people think you are spamming the living daylight out of them. For instance using html messages is, in my opinion, a big no, no.
Try to maintain the time frame of the newsletter. This will significantly increase the response of your readership.
What's more, it's really important you give your readers a way to get out of your mailinglist if they do not like the content. This will save you a lot of spam complaints.
How to promote your newsletter.
The secret turnkey of your newsletter's success is of course its promotion. You can inform about it on your website through banners, pop ups and new windows.
One of the easy ways to go at it is ezine advertising. You simply spend some money, and you can either get a solo, classified, top or bottom sponsor ad. I would try to go for a solo ad as much as possible.
They will also keep in touch with your subscribers, send regular emails to them, and publicize your newsletter through other free sites without you having to install any new software.
I would advise, however, to be independent and send them to your own list. This will make you the most money in the longer run and there are enough solid solutions out there to make it happen.
Stay on the internet to have an idea how much each list is generating. In this way you'll know exactly which ezines you should continue to focus on (read: put money into) and which you can leave alone.
