What's the right length?

While writing the third book of The McConnell Crime Saga, I was worried about each book becoming smaller than the previous. If I were to somehow continue this series for as long as say, Lee Childs' JACK REACHER story, I'd eventually be publishing books two pages long. I can see it now: "A real page-turner!"

I'm keeping an eye on word length for my current book in progress, and it will probably be a bit meatier than STILL WATERS, which was about 67,000 words. BLOOD SACRAMENT, the first of the three books, was 85,000 words. I don't see myself writing a 150,000-word tome. I rarely like to read an undertaking like that, so I don't know why I would write one. But then on the other extreme, if another work of mine seems finished at under 70,000 words, I'll wait before publishing.

I haven't given the novella much thought since my college days, but there's that option. After all, that's the beauty of self-publishing. Like that fast-food franchise, I can have it my way...