This. I want this. The Hellboy formula, as I call it, has worked out really well for Mike Mignola and Dark Horse. The audience gets the characters & stories they want and they can jump off (or on) at any time, stories (mostly) aren't forced in the name of putting stuff out there (i.e., you only put out a series when there's actually a story to tell), the company gets product that's easily collectible in hardcover and/or tpb... everyone wins.
To be honest, I'd like to see DC just come right out and say they're out of the numbers game and just give us a bunch of mini-series (for the lower-tier characters). Instead of promising some ongoing series for a character like, say, Amethyst, why not simply say "We're doing an eight-issue story. It's gonna be great. If you like it, buy it, and when we trade it we'll throw some extras in so you won't feel gypped for double-dipping. And, if you buy enough of it, we'll do ANOTHER eight-issue story about her!"