What are the benefits of having a colony during the Age of Imperialism?

Colonies served many purposes during the Age of Imperialism in Europe. Colonies became a source of nationalistic pride for many countries. Though they arrived late on the world scene, Italy and Germany both insisted on having colonies in Africa during the late 1800s.
Colonies could also serve as a source of raw materials. Britain benefited greatly from New World sugar and timber in keeping its navy provisioned. Colonies could also provide gold, as was the case with Spain's Latin American colonies.
Colonies could also serve as a way to dispose of dissidents— rather than throw them in jail or execute them, move them far away. Britain made the best use of this by having Australia and New England.
Colonies could also serve as coaling stations for one's merchant marine to get somewhere more desirable. Britain maintained a presence in the Pacific in order to have places to refit ships.
Finally, colonies could serve as combatant pools in time of war. France was able to use its North African soldiers during World War I, and many former colonists in Canada fought for Britain in both world wars.