Spinner Collections are special collections that come from Spinners. These are considered the rarest of collections in the sense that players have to win items versus buying them individually. They can also be some of the most expensive: while the cost of a spin token is only 8 Gold - much less than the price of most individual Gold items - the fact that players have to gamble for items can mean a lot of money is spent trying to win specific items.
There was a new spinner every 1st and 16th of every month. But in October and December of 2016 there was a new spinner all 10 days - 1st, 11th and 21th of the month.