Of course, number one, we have the obvious so don't forget about providing real content in your InstaNiche review webpage. I used to delete concepts that I thought were useless back in the old days when I first started, and that's a big mistake, because even though they were useless at the time, they may have become viable in the foreseeable future. There was one product in particular that springs to mind that started as a concept that just wasn't approachable, so I deleted it. Three months later I'm seeing a clone of this idea popping up and it's ads hitting who knows how many tens of thousands of inboxes, and making a heck of a lot of money. You can imagine how I felt about that. Totally missed opportunity. Don't make the same mistake.
The second reason is to give you time to really look and see if this is going to be successful and if people are going to be interested in your Insta Niche bonus package. Look at ways to change or improve your idea. It's safe to say, spending a little time on a concept is worth it if it's going to turn something that was never going to work, into a full-blown successful product.
The third reason, and one of the most important is to keep these concepts is simply because things happen, things change, and they change quickly. A seemingly profitable idea that you couldn't execute for one reason or another, be it a financial reason, or lack of time, resources, whatever it is, this all changes, and when your position changes for the better, it's awesome to have a product or idea go from practically impossible or risky, to a more sure fire hit.
Keep it, keep it all. No matter how ridiculous or far out it might be. Look at this folder and your concepts regularly, change them and adapt them to make them workable in the future when your position changes. Don't doom the idea to your recycle bin, because given time, if your situation suddenly allows the creation and release of this product, and someone beats you to it, you're going to feel as much of an ass as I did in the above example.