But first, let's start off with a short story...
Back in 2010, I discovered an EMD domain name for a niche that only had about 3 authority websites, literally no competition. I bought it, set up a quick website with 2 pages of content and let it sit. I forget about the site and move on. Six months later I remember the site and was shocked to see it was making 5000 UV daily! I immediately revamped the site and added a bunch of hand generated content. The revenue started to come in and I was riding the gravy train. Sometime in 2011, I thought it would be "cool" to show off my success. I posted a thread on another website similar to this one with screenshots, method, and very sensitive details. I thought to myself, heck, no one is going to do what I am doing. Shortly after created this thread, literally a few short weeks, the niche became heavily saturated, and everyone was doing the same thing. Traffic dropped and the gravy train was no more.
To this day I regret ever doing what I did.
Moral of the story? Never reveal your niche/method. Period. Why would you want to have more competition if what you are doing is working already?
Anyways, I hope this helps someone.