Given evidence for both the FITD effect and the DITF effect, I wonder if both are merely special cases of a broader effect that makes people more likely to accede to a request if they've received previous requests from the same source. The low-ball effect would also fit that theory.

Either way, I don't think those wikipedia pages are very good evidence of anything at all, given that they cite work by only one researcher and do nothing but restate his conclusions with a positive slant. I suspect on those grounds that those pages are the work of a sock-puppet or someone caught in an affective death spiral; even if they're not, they're certainly not up to wikipedia's usual (fairly decent) standard.