Everywhere i look in the global tree, duplication is rampant. Merging is a slow process, and in cases where there are discrepancies, inevitably no one has provided any sources whatsoever. We're winding up with duplicates being created faster than they can possibly be dealt with, and unresolved disagreements are all over the place. I don't know how all these dupes are getting into the system, but they need to be prevented up front. You can't just rely on people to spend countless hours clicking the "This person has too many parents" button just to merge one person, then find two more who need merging, which leads to six more, and on and on. It's out of control.
I can just imagine people out there with their genealogy book that's been in the family for ages. They get on Geni without bothering to learn how to use the site, and spend 8 hours entering people straight from their book, and it'll take 16 hours just to merge just the most basic duplicates. There needs to be some kind of check when a person is being added, prior to saving the record, that pops up and says "STOP!! This person already exists with the same year of birth/death, same parents' names, etc., let us link that for you" and be done with it. *Before* they enter hundreds more dupes.