One of the key concerns for someone starting out in email marketing is getting people to actually sign up for your list. The return on investment is terribly low for email lists that have been purchased or rented, so these are generally not worth your time at all. But it can be challenging figuring out how to get people to opt in to receive your mailings.
With regard to value, you must make it clear to your visitors what they have to gain from joining your mailing list. Try to use language that focuses attention on the benefits of membership. For example, you might describe the type of useful information that can be expected as a regular part of your email marketing campaign, you might offer a specific bonus for signing up, or you might offer a desirable prize “for one lucky subscriber.”
The second issue you should take into account is the ease with which a new subscriber may sign up to your list. There should be a clearly visible sign-up form on every page of your website, and the form should not demand too much information. If you need extra information in order to make the mailing list more useful to them, it would be a good idea to explain how it will help the subscriber to provide that piece of information.
Once a web site visitor or a visitor to your brick and mortar business has been exposed to these two factors, they will likely sign up for your mailing list. Provided that the value you have offered is one that they find desirable, and you have made sign-up easy and accessible, there really is no reason why they would not sign up for your email list.