Thrallherd + BoVD Sacrifice loop = infinite Limited Wishes + Dark Gold + Dark Exp + pile of commoners stuff.
Not bad.
Obviously pales, relative to specific 6s and 7s, and higher spells, still not bad.
There was a TO-board thrallherd chain build, that explored how big that follower semi-loop got.
No where near as big as an Epic Followers type thing.
It's questionable about how to get followers to "worship" you.
Charm Person + Hypnosis = Fanatic ... but how long and how much re-fanatic-ing to keep it up?
The one Dragon PrC gets Divine Rank zero going, but around level 42 (officially).
Ice Assassin cheese gets (at least) one DvR too.
Yes I know about pun-pun's infinite dvr ... as a best case scenario.
How these all interact, shrug shoulders?
iirc - there is a way to get a Loop going on the level 6 followers, then getting Leadership themselves at max.
I don't remember how it works.