Daily Points (DP) can be collected by logging in daily, selling monsters in the auction house, being the first to conquer a Tower, and progressing through the game.
Auctions are conducted with DP. Listing monsters requires a deposit fee and winning auctions will incur a commission fee as well.
DP can be used in the Enhance Skill and Acquire Skill process. Spending DP in the Enhance Skill process offers a small chance for an EXP boost. Spending DP in the Acquire Skill process will have a smaller chance of success than CP.