I have concluded that BlondeBomber and megamiles have too much time on their hands but I do thank them for doing those calculations - very interesting. Here are my tips for using miles:

1. If you have to go somewhere "spur of the moment" and it is the off-season. I have called up and used miles within 7 days notice. If I had purchased a ticket, I would have been charged a fortune because there was not a 7 day advance.

2. I use them after I have gained an elite status with that airline for the year. That way, I am not ruining my chances of gaining elite status by using miles instead of earning them.

3. Never use miles if you get a killer deal such as an e-fare. Those cheap, last minute deals are the most economical way to earn miles.