I started in 2011 and I did my first ever mile runs to get silver status in AA and One Pass at the end of the year. in 2012 I did the same to get Gold Status in AA and Platinum status for United. But in booking those final runs for 2012 I decided to book 3 Mile runs for 2013. That gave me a nice jump ahead though I'm only going to reach Gold this year for United and I didn't fly any AA this year. The 3 mile runs cost me about $600 and I ended up with 18,000 EQM.
I'll mile run anytime there is a good deal and i'm not planning to go on vacation. So for the most part that is what I plan all my mile runs around. I don't like doing end of the year mile runs, though I did do 2 in december for my Gold Status now. I booked them a couple of months out though. I would hate to be looking for a deal right now.