The real real test is to get an audience first3 Seconds and under is good. Anything longer and you'll start to get drop off. The real test is compare videos you have without an intro and the ones with and see what the audience retention is.
The real real test is to get an audience first
I agree, just takes awhile to get to the point where you're regularly getting a few hundred views per videoeven with a few hundred views per video you can get some decent statistical data to make improvements.