sweeten (up) the pot

To make something more enticing, alluring, or attractive, especially from a financial perspective. He was still unsure whether he wanted the job, so the company offered to sweeten the pot with an excellent pension plan. Don't be afraid to sweeten the pot with a little bit of pocket money if your kids are really unwilling to do chores.

Fig. to increase the amount of money bet in a card game with hopes of encouraging other players to bet more enthusiastically. John sweetened the pot hoping others would follow.

Make something more attractive financially. The term dates from about 1900 and alludes to card games such as poker, where it means to add money to the pool. It is now used figuratively, as in “To sweeten the pot for members, the museum offers a 10 percent discount in its gift shop.”