独立点击送达率的英文：
CTR

We know from above that you need only a rank number of .02 (your maximum CPC x initial 1% CTR) for the top position. What if your CTR increases to 2%? For the top position, you will only have to pay $1 (CPC x 2% = .02).
从上例我们可以看出,你只需要使排名值为0.02(最高点击费×1%的实际点击率),便能使你的位置排到最高.如果你的实际点击率增加到2%会, 排在最高位置你只需要付1美元的点击费(点击费×2%=0.02)

Ad placement is based on a combination of maximum cost-per-click (CPC -- how much you are willing to pay per click) and clickthrough rate (CTR).
广告排列的位置是基于最大点击费(每次点击你愿付的上限)和有效点击率的基础上的。