It's probably a bit more advanced than this. We actually put out a platform about 10 years ago doing it (going to have to go see if they violated our patents lol) Here's our platform so you can see how we were using it (and I suspect they are doing it roughly the same - if you look at things like the skateboard & football, you can see you don't even need flat blank spaces - we analyzed videos & recommended spots, then auto inserted brands): http://dolo.co/