Every new day that you visit you are going to get a new daily reward. There are seven days that you get a distinct reward for, and there are some actually beneficial ones too! On the seventh and thirrd day you get some free heroes, so it's a great and easy way to collect them and include them to your collection. On the fifth day you will get some VIP points, which are a very helpful resource in the game that you will require to more ended up being more powerful. The sixth and second day rewards are some Diamonds, which you should absolutely gather to summon much more heroes.