TAC shouldn't be part of that computation. It's an expense, not revenue. (Yes, it's confusing that it's in the same table as the revenue numbers, but so is the headcount and you wouldn't try to work it into the equation somehow.)

Also, if you only consider the search revenue you'll err in the opposite direction. It's 55% of their revenue, so pretty soon not even a normal majority. You should look at the "Google Advertising" line.

Thank you!