i would absolutely love pitboss, i work full time (nights even) and have friends who work day, and others who are in other countries, pbem servers are a lifesaver for us. People can drop in or drop out at will. Turn time limits, AI takes over a turn if you miss your deadline for some reason. If everyone happens to be on at the same time it temporarily becomes like a normal MP game, and goes back to pbem the moment someone leaves. Just awesomeness that ya don't see anymore since Stars.
Some friends of mine still haven't bought the game, and won't, until pitboss comes out for it (or some equivalent) because that's the sole reason they are interested, multiplayer games w/buds. I can enjoy the game single player, but i pretty much need something like pitboss to play multiplayer w/my friends. (plus, it allows one to play larger more epic games over long periods of time, w/out hassle). A low-overhead dedicated server setup like pitboss was for civIV makes it a snap to just permenantly host a game w/out stressing your machine or bandwidth. I might even buy some extra copies for friends if pitboss is ever released for friends who've never experienced such a thing, get them hooked!
There's a whole pbem niche crowd to appeal to here, and w/out much competition out there, its free money. Draw in that pbem crowd, create new converts to it, and be the only game in town for them.