In case you, for any reason, end up with multiple Sessionize accounts, there's an easy way to merge them together. While logged into the account you want to migrate from, click on your name in the top right corner of your Sessionize profile and select Migrate to another account. Then simply follow the on-screen instructions.
Before finishing the account migration (merger), you'll see an overview of the changes that are about to happen - what's getting deleted and what's staying. If things look like you would want them to, finish the process by clicking Migrate Now.
When migrating accounts, you'll end up with a singular speaker profile. However, all of your previous speaker engagements are saved, even if they originate from the migrating account.