Reading an article this morning about American Spirit Cigarettes adding ammonia to freebase nicotine.
(http://www.capitalnewyork.com/article/florida/2015/10/8578484/natural-tobacco-company-faces-federal-suit-deceptive-advertising)
So fresh cigars whether people detect ammonia in them or not I think we all agree it is present (or has been), now reading this would insinuate that as the ammonia disipates the nicotine level would drop until we reach a point of levelling out.
Now depending on what you're looking for from your cigar this could correlate to the aging questions that we all have. The timeframe it takes for the ammonia to disipate the nicotine to stabilise and the blend to hit a truly natural state. Is this the sweet spot?