Using a QR-code on the YouTube channel banner
After Alexa's video about first impressions on the channel homepage, I changed the banners and also included a QR-code for people that watch on TV. They don't see the description and might not even be able to click on a link. The QR-code can solve that issue, since viewers might have their phone nearby. The QR-code is outside of the "safe area" (1546 x 423 pixels) and therfore only visible on TV, not on mobile or laptop. For my MX5info channel, the call to action is to visit the website, whereas for the language learning channel, the call to action is to request a free example lesson to get acquainted with the learning environment. I wanted to share it here, since you might benefit from a similar approach. This idea can also be used in regular videos for a call to action.