This helps to make sure that no one is subscribed without their knowledge or consent. Potential new subscribers may want to see back issues of your ezine. Current subscribers may want to look at previous issues as well. Look for a list manager that will archive your mailings automatically. Flexible subscribe options.
Some people are more comfortable with email, others with websites.
If people are given the option of using either method to subscribe, you'll be able to increase your readership more quickly. Understanding who your readers are is a big step to providing information that's relevant and useful to them. Some list managers will allow you to ask your readers for information such as gender, occupation, Internet experience, and so on. This is also good to know if you ever decide to start charging for ads placed in your ezine in the future. Also find out what type of support you'll have.