You can have a video trailer show to all unsubscribed visitors to your channel. Your channel trailer is like a movie trailer - use it as a way to offer a preview of your channel's offerings so viewers will want to subscribe. 

By default, ads won't appear when the trailer is playing on the channel page in the trailer spot (unless the video you've chosen contains third-party claimed content). This helps keep the user focused on learning about and subscribing to your channel. If the viewer is already subscribed to your channel, they'll see a video under "What to Watch Next" instead.

Set a channel trailer

Before you start: To set up a channel trailer, you have to first turn on channel customization for the channel.

1. Upload the video you want to be your channel trailer.
2. Go to the channel you want to manage.
3. Go to the "Home" tab.
4. Click the "For new visitors" tab.
5. Click Edit .
6. Select Change trailer or Remove trailer.

Quick tips for creating channel trailers

• Assume the viewer has never heard of you.
• Keep it short.
• Hook your viewers in the first few seconds.
• Show, don’t tell.

Change or remove the channel trailer

1. Go to the channel you want to manage.
2. Hover over your channel name and click the edit icon .
3. Select Change trailer or Remove trailer.

* Nguồn: Youtube