Sumproduct function was very often used before function sumifs was released. It can sum range of cells with more conditions. Main advantage of this solution is that you can use combination of vertical and horizontal conditions. Disadvantage of this function is that it need to much perfomance. So it is not suitable for bigger solutions.
This function can be used of course as standard sumproduct formula where (a, b, c) sumproduct (d, e, f) equals (a*d + b*e + c*f).