Right but then imagine you had 3 products each with the same max entries and same bucks per entry and the same prize quantity say of 3.
Say when you look, all 3 product currently have say 10 entries so far.
If you placed 3 bids all on 1 product, then you chance of winning the 1st product 1st price is 3:13, but then you chance of winning the 2nd item in 1st product is zero, and again zero. So your chance is 3:13.
But if you placed 1 bid on each product, then you chance of winning the 1st is 1:11, the 2nd is 1:11 and the 3rd is 1:11, hence the chance of winning something is 3:11.
3:11 is bigger than 3:13.
You see the problem if when winning you are barred from that same item.
So define random.
If you put say 3 entries in 1 product you chance of winning the 1st