Have you guys considered maybe setting up subscriptions for X amount of races rather than X amount of days? Seems a little silly that someone in a 3 race a week league has to pay the same as someone who is in a 7 day a week league. I know you have the choice to be in whatever league you want but I don't know, just throwing around some ideas.
Was thinking it would be a good idea to pay per X amount of races (like basically extending the 2D trials so you can use them whenever you see fit?) .. $10 for 30 2D races or something rather than $10 for a month. Firstly your subscriptions would last longer, and if you chose to only use live timing for a race (or if you were away for a weekend and simply couldnt use 2D) then you're extending the time frame that you have 2D for since you're not using it.
I guess the downside is just that, iGP would be losing income since everyones 2D would last longer, but maybe it would appeal to more users and get more people subscribing in the first place.
Edit: Although I guess if you started doing this, it ruins the "spectating" function as you'd have to chew through one of your 2D races in order to watch a race (unless there is some way to make the spectator method not use one up?)