A few threads are currently discussing how to retain new visitors to AH...
I suggest opening one very limited, free visitors arena to let the inquisitive public get a better taste of AH. Others have mentioned that two weeks is not a lot of time to make a decision about a subscription, or about shelling out cash for a better PC and sim gear.
The arena could be based on the following specs:
Only two sides to the arena.
Only two iconic aircraft available from around the Mid War era, e.g. Spit 5 on one side, and 109 F on the other side (or whatever matches up pretty well).
The arena only supports air to air combat, no land grabbing.
No perks awarded, but name in lights would appear.
No stop in the hangar, just an automatic spawn with max load fuel and ammo (perhaps even an air spawn).
No bombs, rockets or DTs.
General functions like clipboard and com could still be available.
This arena would be perpetual free advertising without giving away the store.
Free arena players who do not subscribe cannot access any other AH activities.
Best.
[EDIT: Now that I think about it, might as well put two tanks in the arena as well, with the same kind of limitations.]