Why did more Native Americans support the British side rather than the American side in the Revolutionary War?

The Native Americans believed that if the British won the war, they would keep Americans off of their land.
The British paid Native Americans in supplies and money to support their side and to fight against the Americans.
The British eagerly tried to gain support from the Native Americans, while the Americans resisted their support.
The British promised free land in Great Britain to Native Americans, in exchange for their support during the war.