"Waiting for" list vs. Tickler
I've been incrementally implementing more GTD bits into my workflow at work. Some of these bits are the "Waiting for" list and the Tickler system.
For one example, with the e-mails I send, if I will need to "keep an eye" on them for later follow-up (if I don't hear back) I will BCC myself on them, and an Outlook rule puts them into my "Waiting" mail folder. I can then review this folder periodically to see whether I need to ping anyone on any of those topics.
This works fine except I end up with a long list of Waiting mails that I have to look through every time I scan the folder. This is exactly the kind of repetitive work that I believe the GTD system should be helping us avoid.
Is there any reason not to stick "Waiting for" items into the Tickler, for example: suppose I need to hear back from Joe by Friday. I could BCC myself on that, and stick my copy into a Tickler mail folder for Friday's date. When that day comes, I empty the folder out and "ah! I need to ping Joe for a response." Just like a physical Tickler system.
I guess my question is, why have these two separate systems -- Waiting For and Tickler -- to begin with, instead of just using the Tickler?
I think there is a small philosophical difference between the two, where the Tickler is technically for things that don't require action now, but might (or will) require action later -- meanwhile the Waiting For list is when you have no action to take other than reaching back out for a response. But is this small difference worth keeping two separate systems? Or am I missing a subtle yet important detail?