The French Government didn't really want the Louisiana Territories. They didn't have the ability to control it; they needed all of their troops in Europe to fight Napoleon's wars. So selling Louisiana to the Americans killed several birds with one stone:
- It got rid of a territory that French Governance and Napolean didn't have the money to administer
- It gave Napolean a nice infusion of cash
- It helped cement the alliance between the US and France
- It strengthened the US, especially giving them additional ports to control. That gave the US an incentive to strengthen its navy.