Billed as a necessary step to, “combat fraud and other malicious activities that can weaken everyone’s play experience,” Blizzard has made the decision to limit players who just purchased Diablo III digitally through their store.
New buyers will be limited to the first act up until the boss, unable to take part in global matchmaking (only with other Starter Edition players), will max at level 13, and cannot access the real money auction house.
After the 72 hour waiting period, these restrictions are lifted and players can take part in the game as intended.