The Screencast-O-Matic recorder allows one to upload recordings to various services like Youtube, Vimeo, or to Screencast-O-Matic's own hosting. In order to add these services, please see the instructions below.
Add more upload options
To see more upload options like YouTube when you first start using Screencast-O-Matic, you must click this icon on the recording's page to show the other options available for upload:
And here is the dialog that will allow you to add the ability to upload your recordings to many different services.
You can watch a tutorial here.