Niche of MUD nowadays is mainly about people who don't have time, attitude or ability to play graphic extensive games. This could include ppl who simply have no time because they have too much business/family/etc.

Remember how the peak of MUDs popularity was when universities/schools had open internet access and tons of students played. The reason they did so because they could not play anything other than MUDs. It might be the same nowadays, except that all the students have PCs at their home now, but some grown-up people who have PCs have no desire to play graphical games, because they're "childish"/require time/money investment or for whatever other reason.

I for one play MUDs because it doesn't require me to run anything on my computer, and I'm totally free to browse other windows and work simultaneously.

P.S. I understand that was not really a "CF marketing plan", but just a topic to think on when targeting your audience.