People are more likely to act when you ask for one specific thing.
“Save this for your next grocery run.”
Asking for five things at once, or asking before you’ve given any value.
How to use it
Pick the action that fits the video’s goal: a save for a useful list, a comment for a question you actually want answered, a follow for a series. Make the reason obvious (“Part two is tomorrow”), say it once and keep it short. Some of the best calls to action are built into the payoff instead of tacked on after it.