The primary expense of e-discovery comes from the document search and review process; most estimate that it constitutes from 60% to 80% of the total. The core expense of the review process comes from the final manual quality control checks of each document to be produced to verify relevancy and to protect confidentiality by redaction and privilege logging. Confidentiality protection is an enormous problem in litigation. See Anonymous, An Open Letter to the Judiciary – Can We Talk? Parts One and Two.
Further, you cannot just dispense with final manual review. As I explained in my series Secrets of Search, Parts One, Two and Three, we are not going to turn that over to the Borg anytime soon. I’ve asked around and no law firms do that now. No experts advocate that approach either, even the most extreme advocates for automation (of which I’m one). The only exception I have heard of is in non-litigation circumstances, such as second reviews with production to the government. Automated review is nowhere near good enough to go it alone. You use predictive coding to speed up the final manual review to be sure, but only a fool (or con artist trying to get at a producing parties secrets) trusts coding software today without human verification.