[x-complexity]

> How about actively keeping that at 0%?

Practically impossible. A sufficiently well-developed bot is indistinguishable from the least technically-savvy legitimate users that clicked on an ad. Unless you have a novel way of filtering out the 2 from each other, the costs for performing such filtrations compound linearly at best & exponentially at worst.

[floomk]

It should still be their goal, instead of some arbitrary percentage. Or I suppose they could offer everyone a blanket discount for the fraud percentage.