People think you get dopamine hits when you find cool stimulating things. You actually get a steady drip while seeking, it’s what keeps you transfixed looking for the next thing. And as this shows a variable reward gives you a stronger drip:

https://liveinnovation.org/dopamine-more-than-pleasure-the-s...

I figure a big challenge for TT is they must send you less good stuff to rate it. They probably hold off doing that until you appear hooked. You wouldn’t want a new user to get a bizarre/lame video with 5 views.