Three reasons.

1. “Some $18 million in tickets have already been pre-sold for Disney’s 3-D Hannah Montana & Miley Cyrus: Best of Both Worlds Concert movie, which opens tonight at midnight,” says Entertainment Weekly.

2. “Disney registered the following domain names just the other day: NationalTreasure3DVD.com and NationalTreasure4DVD.com. This means that, yes, most likely plans are already underway to shovel out two more National Treasure sequels,” says Cinematical.

3. This.