It does not (necessarily) bring good (in the form of substantial, and tangible results), but it is the meant whereby something is extracted from the miserly persons. (Using translation from Muslim 1639c)
نَهَى النَّبِيُّ ﷺ عَنِ النَّذْرِ وَقَالَ إِنَّهُلَا يَأْتِي بِخَيْرٍ وَإِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الْبَخِيلِ