For me.... a few times per day a new banner will appear at the bottom of my game screen with options
to watch for cash or boosts... recently I was able to keep watching vids... but learned that if I tried to
watch more than one I didn't receive any reward at all... so now it's just "one and done... that's what I say...
well... I said it once..."

I always jump on the "Watch and Win" logo at the top for tokens when it appears...