Have lots of links in your newsletter to special offers on your website. You only have 100 people who have signed up. Therefore if only 1% (1 person) buys from your site then you are probably doing well!
You may also want to use online software like Constant Contact to create and send out your e-mails. The software is quite limited but you can receive some good stats about open rates, click-through rates, etc.
As you probably know it's a numbers game. Boost your subscribers and your CR will increase. However I've seen ezone campaigns with few subscribers and have a conversion rate of 10%. It's all about the copy of the ezine. There are a lot of different areas to concentrate on when writing ezine copy. Your ezine has to grab your subscriber’s attention, so they will read the entire thing. You need to walk in their shoes. Ask yourself, "What is in it for me". Now pretend that that is the customer asking the question. You have to appeal to the customer. You are asking (essentially) them to purchase something from you. They don’t even know you. You have to establish yourself on the topic. Probably the most important issue is how well you write the "intro" or the "headline". Do some research on writing ezine copy. There's a ton out there. Good luck!
sell packaged deal, for ezine subscribers only. have, for example, a watch, knife, and mag light combo kit. but allow the customers have the ability to replace items if need be. upsell upsell upsell. just my