You use the expression ‘Brownie Points’ to indicate a nominal mark of achievement or some kind of kudos for the performance of a positive or creditable act.
Example in use: “I’m going to earn plenty of brownie points for taking care of all these chores without being asked.”
The term ‘Brownie points’ is a direct reference to the Brownies, a group of junior Girl Scouts who earn rewards based on merit. The term has been popular since the 1940s; an early example comes from a 1951 Los Angeles Times article called Brownie Points – A New Measure of a Husband: “You don’t know about brownie points? It’s a way of figuring were you stand with the little woman – favor or disfavor. Started way back in the days of the leprechauns, I suppose, long before there were any doghouses.”