Control of Costs per Click to meet ACOS Objectives
Depending on the ACOS objectives the CPC have to be maintained below a certain level. The bids set for clicks are, however, not necessarily what sellers actually have to pay for the click. Sellers only have to pay the amount that is necessary to be the highest bidder.
Seller A bids 10 Cent.
Seller B bids 5 Cent.
=> Seller A only pays 6 cent per click.
Sellers can therefore usually bid around 10% more than what their own calculations to meet their ACOS objectives suggested.
The CPC will not be raised by your own bids for the same keyword in other campaigns.
Standard Costs per Click
The minimum price per click is 1 Cent.
In most product categories clicks for Sponsored Products on the first page will cost around 7-30 Cent.
Some keywords with intense competition (eg. iphone case) will lead to CPC in excess of 1$. For those kinds of keywords the ACOS objective is usually not to be as profitable as possible, but to simply break even.