It's a mix of product/tech knowledge, calculations upstream of how much Google needs from the YouTube business, and some savvy in understanding the people in th

It's a mix of product/tech knowledge, calculations upstream of how much Google needs from the YouTube business, and some savvy in understanding the people in the YouTube organization. Another mix of people in the same situation would probably come up with a different number, and neither would necessarily be wrong, or necessarily under- or over-analyzing relative to their capabilities.