The lists Gmane provided where primarily various open source projects and similar.
Gmane doesn't host the mailing lists itself. Instead it provides access to lists hosted elsewhere. It does that by subscribing to the list and then saving the incoming messages. It then provides access to those messages using NNTP, or various web interfaces (different layouts etc). IIRC it may also provide RSS. It also allows posting to the lists by forwarding the message.
The benefits are great as a reader since this is one place you can to read many lists, and you don't have to subscribe to each one etc. (Some may require subscribing for posting though.)
The other benefit is that if you get people on mailing lists asking why use something archaic like email when the hotness is various web based boards, and the project is immediately and unconditionally doomed because that is what people are used to. You redirect those folks to Gmane where one of the layouts is web board style.
Gmane doesn't host the mailing lists itself. Instead it provides access to lists hosted elsewhere. It does that by subscribing to the list and then saving the incoming messages. It then provides access to those messages using NNTP, or various web interfaces (different layouts etc). IIRC it may also provide RSS. It also allows posting to the lists by forwarding the message.
The benefits are great as a reader since this is one place you can to read many lists, and you don't have to subscribe to each one etc. (Some may require subscribing for posting though.)
The other benefit is that if you get people on mailing lists asking why use something archaic like email when the hotness is various web based boards, and the project is immediately and unconditionally doomed because that is what people are used to. You redirect those folks to Gmane where one of the layouts is web board style.