What exactly is Multi-Account sending and Account-Chaining?
A. Multi-Account sending allows you to cycle through accounts when sending messages. A single account is limited to only a few messages every 15 minutes. With Multi-Account sending, you can set up Tube Toolbox to rotate between multiple accounts when sending messages. This allows you to send many more messages before your limits are reached. You only need one account upgraded to a Professional Account to use Multi-Account sending. BUT, you must ALWAYS use the Professional Account in the sending rotation. So if you are promoting more than 1 product or channel, it would be in your best interests to Upgrade additional accounts.