Another nice advantage for readers is that after they download a Word file, they can edit the text and graphics for their own purposes, which is especially useful for research. One problem is that unless readers know you and trust you, many of them will be reluctant to download a file because of a possible virus attack. And, of course, not everyone has Microsoft Word, so some users will be unable to read the newsletter. Again, though, you don't want to load the newsletter with gratuitous graphics that take a long time to download. The most valuable feature of HTML is that you can create a nice layout with typography and graphics that do not require special software to read it.
Most people can learn that process fairly quickly.
The latter is read only by those who receive the e-mail. The Web version can be viewed by anyone who finds the site. So you can gain a wider audience by getting the newsletter indexed on popular search engines such as Yahoo and Google, placing it on specialized search engines in your field, and publicizing it in other media that your target audience uses. The disadvantage is that people who aren't looking for it probably won't find it. So you must remind or motivate your audience to visit the website when a new issue of the newsletter is published.