The Purpose of Waiting For
For me, the purpose of Waiting For is when I am waiting for something (from a person, the season to change, a new product to be released, etc, etc) and I do not know when it will be done.
If I put the reminder in my tickler for next month and it gets done next week, there is a potential disconnect with finding the original. I absolutely use the tickler where it makes sense. For example, if I want to be reminded of something on a certain date or I know I'll want to follow up with someone on a certain date if it isn't done.
As examples, my current Personal waiting for includes a list of books/movies that I've lent/borrowed, buy a new lamp when Ikea opens, call my Aunt to invite her for dinner to celebrate when we've sold our house, and several online purchases I've made for which I'm waiting for delivery.
At work, I've got drafts that I've sent up to my boss, specific training/experience I'm looking out for for my staff, meetings I've requested, etc. By having these in my list, I review them regularly and can identify if I need to follow up with something.
You could do the same with paper in a tickler file but I find having this list integrated with my system invaluable. I often frequently alternate from NA to Waiting_For and having it in my system makes this very easy.