Leagues- These can determine how much loot you get per raid since these have a certain amount of people getting  up trohies to have a better loot bonus. The champions loot bonus is 120000 gold and elixer plus a total of 1200 dark elixer to go with each raid so town hall sniping is worth it. Trophies can determine also whom you should attack. When you are at masters league you will attack people with level 10 town hall so you can see why a person with a level five town hall would be raided everyday. You can get gems for having 1250 trophies. Then if you join crystal league then you can get 250 gems. If you join masters you can get 500. If you join champions you will get 500. If your clan is the top three. They will get gems for the top ten of the clan so stay back for your non- upgraded clan members. Trophies are rediculous how they affect you so don't go too high or you will lose all your loot.