I wish people would include sample size when talking about conversion rate lift. Otherwise for all we know the measured lift is noise and isn't repeatable. Doubling conversions from 4 to 8 out of 100 visitors means much less than 400 to 800 from 10000 visitors.

That said, it makes a lot of sense that a marketing video helps people learn more about your product, get more excited, and feel more comfortable taking the desired action.