I think when you upgrade a wall it should give you experience. The amount of experience should be twice as much as the wall level, for example:
upgrading a level 7 wall to level 8 would give you 16 experience or
upgrading a level 10 wall to level 11 would give you 22 experience.
please comment what you think
(and don't say that we don't get experience because its an instant upgrade, i spend 500k for each wall just for a few more hp and don't get a drop of experience(which you would get if you upgraded any other building on the game))
thank you:)

