That *is* a cool idea. Subscription services are the way to go, BTW...recurring revenue is always better than having to go back and ask for more every time you have a new product. They don't work for everything, unfortunately, and they make you stick to deadlines. Not sure how Monte Cook's Dungeon-a-day thing worked out (he recently stepped out of it and turned it over to ?Rite Publishing?) but that was a pretty specific enterprise. A creature-a-day (or spell-a-day or NPC-a-day or whatever) might have longer legs...it's something everyone can use in their games. I think I remember the thing Midgardsomer was talking about (they did it with recipies and other things too) - got cards in the mail and they fit into this little plastic filing box. I would totally think about something like that for interesting beasties (or NPCs or plot hooks) that I could use in my game.
M