# Discrepancies caused by trimmed costs

• ### Question

• We are experiencing discrepancies between totals retreaved in different kind of reports. If we calculate total costs by summing all costs generated by keywords we get one ammount. If we retreave total cost by getting account report we get another cost. If I'm right, it's caused by costs trimmed to two digits after comma.

For example, we get following info:
<Clicks>14</Clicks>
<AvgCPC>0.09</AvgCPC>
<TotalCost>1.21</TotalCost>
If you divide TotalCost by clicks you get 1.21/14=0.0864... which is not equal to 0.09.
If you multiply AvgCPC by Clicks you get 0.09x14=1.26 which is not equal to 1.21.

What is a right value in this case? Probably no one.
Is it possible to extend precision of costs to 3,4,5,etc digits after comma?
Is there way around this problem?

Tuesday, August 7, 2007 8:04 AM

### Answers

•

With proper rounding to two places, .0864 is equal to .09.

And .0864 * 14 equals 1.2096, with two-place rounding comes to 1.21

I doubt you will see this behavior change any time soon. But as you see how we are doing the rounding, you should be able to take this into account when doing your own calculations. I think the key would be to choose one method, and stick to that for consistency.

Hope this helps.

Jeff Dillon, Microsoft adCenter API Technical Support

"Meet me at SES/San Jose Aug 20-23. jeffdillon_ses@hotmail.com"

Tuesday, August 7, 2007 5:21 PM