We have added a Gift Upgrades feature that allows you to gift an account upgrade to another member, just in time for the holiday season. You can see the gift option when going to the Account Upgrades screen, or on any user profile screen.
However, I do need to mention that in one GS game I got my spy up to doing -35 loyalty. It was a level three spy, so do they gain +5 to the effect for each level they have? Either way -35 makes them MUCH more useful for flipping cities.