We have the mailing list. Why do we need a newsgroup?
In the US we make Ford, Chevrolet & Chrysler. Why do we need Mazda, Honda, Nissan & Toyota?
They all make cars. But, they all don't make them the same. Some people like the way the Japanese build cars better. Some like the way Americans build cars better. There's room in the world market for all, and it gives everyone more choice having more manufacturers.
The car maker analogy is a lot like that between private mailing lists and Usenet. Broadly speaking, they both perform the same function, just differently. Having both gives everyone more choices.
Here Is A Comparison Between Them
|Instantly available to anyone with Usenet access. Just pick your topic off a list available on every news server. You can check a box in your reader and each time you open your reader, it will automatically download article headers for the checked groups. A good place to discover the existence of a mailing list BTW.||Suscription is required. Before you can subscribe, you first have to know one for a topic of your interest exists. Once you subscribe, retrieving any mail causes all mail to be retrieved.|
|No reason you can't utilize Usenet and still subscribe to a mailing list.||No reason you can't subscribe to a mailing list and read Usenet too, as long as a group with the right topic exists.|
|Takes up no space in your mailbox or on your hard disk.||All list mail is downloaded, and you must delete everything you don't want to save. List posts may overwhelm a particular post of interest, making whether it arrived or not difficult to determine without proceeding through all mail before you might be ready to.|
|Posts may expire before you get a chance to read them. If you don't have time to keep up, posts don't continue to pile up to remind you you are behind.||Your list mail won't go anywhere except at your direction. It can pile up fast if you don't keep up with it.|
|Nothing reaches your hard disk unless you take an affirmative action to cause it.||Your mailbox can easily become flooded if you don't routinely keep up with incoming posts. Using the digest form of the list helps reduce incoming quantity to a manageable level, but if you save posts, you cannot cull out those on topics you don't want saved, which is a big space waster.|
|Making a post to usenet makes your email address public for the whole world, including SPAMmers, to see. You can make use of anti-SPAM addressing, in which case you can prevent everyone from seeing your address.||Your email address only remains private to the rest of the world. List mail doesn't get through without a valid address, so everyone on the list will know your address. SPAMmers are allowed to subscribe, so technically, they do have access to your address if you ever post.|
|SPAM.||SPAM is not a material problem, but the noise level on a mailing list can become rather high. See flames.|
|Flames.||No less common, and sometimes well fanned.|
|Off topic posts.||Hardly uncommon.|
|Threading of related posts makes following spawned discussion easy.||Choosing the list digest format prevents threading. Even with the interactive method, you may prefer viewing saved messages by date, rather than thread.|
|DejaNews & other newsfinders make searching for topics of interest among Usenet postings very easy.||Finding posts of interest in mailing list archives can be problematic.|