We use these brownie points as a reward.  They can be for exceptional work, or even just a great effort.  They could be just for completing a full day of work.  Once we hit 100 points he'll get to make brownies. 

Below, in the blurry pictures we use paint swatch cards as book marks.  After each chapter he adds a sticky dot.  It's a fun way to mark progress although he doesn't need it as an incentive - he enjoys reading just for the sake of reading.  When he's done we put them on the wall and our goal by the year end is to have a whole rainbow of colours up there.  He's got 2 more in the works right now.