The number of subscribers you have however, will determine whether or not it is worth their while. One with just a few hundred is not a strong contender, unless it goes to an extremely small market. It takes quite some time to build a substantial number of subscribers, and in the beginning, you will probably earn little or nothing from your endeavor. Once you have a thousand or so subscribers, you can then begin to market your advertising space. In order to do this, you must publish on a regular basis.
Many people start by buying ad space from other publications.
Some also send their articles to other publications hoping they will be published with their credits at the end. Some Newsletters claim to have several hundred thousand subscribers, and they haven't been around that long. Spam - pure and simple. They either extracted your email addresses from the web, or purchased their list - yes some ISP's do sell their email addresses. They then send you their publication, and make it virtually impossible to unsubscribe.